1 

## DRAFT

**COST -**  **EFFECTIVENESS OF A**  **40 % BODY AND CHASSIS**  **WEIGHT -**  **REDUCTION GOAL IN LIGHT -**  **DUTY VEHICLES**
Sujit Das En ergy and Transportation Science Division Oak Ridge National Laboratory Prepared for Li ghtweight Materials Office of Vehicle Technolo gies U. S. Department of Energy



### June **200 9** 

OAK RIDGE NATIONAL LABORATORY Oak Ridge, Tennessee 37831 managed and operated by UT - Battelle, LLC for the U.S. DEPARTMENT OF ENERGY under contract No. DE - AC05 - 00OR227251 **Cost -**  **Effectiveness of a**  **40 % Body**  **and Chassis Weight -**  **Reduction Goal in Light**  **- Duty Vehicles**  **Oak Ridge National Laboratory**

**June 200**  **9 1.**  **Background** With the recent higher gasoline prices , new emission and fuel economy regulations that require b y 2016 a 30% reduction in CO 2 and other emis sions and an average fuel econom y of at least 35 mpg , the pressure to lightweight vehicles is stronger than ever before. The next few y ears will see considerable light - weighting across the automotive industry . Vehicle lightweighti ng represents one of sever al design approaches automakers are currentl y evaluating to i mprove fuel economy . L ightweight i ng is ty pically accomplished b y downsizing, integrating parts and functions, substituting materials, or b y combin ing these methods. Li ghtweighting Materials ’ (LM ’ s ) component of the U.S. Department of Energy ’s Vehicle Technol o gies program focuses on the development and validation of advanced materials and manufacturing technologies to significantly reduce automotive passenger vehicle body and chassis weight without compromising other attributes such as safet y, performance, recyclability, and cost. The specific goals of LM are to develop material and manufacturing technologies b y 2010 that, if implemented in high volume, could cost - effectivel y reduce the weight of pa ssenger - vehicle body and chassis sy stems by

50% with safet y, performance, and recyclability comparable to 2002 vehicles. In order to achieve this long - term weight - reduction goal , LM has set annual intermediate weight - reduction goal s, starting with 10% in F Y2007, and finally achieving 5 0 % by FY2010. This paper is a follow - on to an earlier study which focuse d on the 25% body and chassis weight - reduction goal of FY2008 (Das 2008). The present study emphasizes the assessment of cost - effectiveness to achieve th e desired goal of 40% body and chassis weight reduction in FY2009 . To achieve its long - term weight - reduction goal , LM has prioritized its research areas in several lightweight ing materials including advanced high - strength steel, aluminum, magnesium, titani um, and composites . Composites includ e metal - matrix materials and glass - and carbon - fiber reinforced thermosets and thermoplastics. Over the past several ye ars, the LM R&D portfolio has included a ssessment s of various lightweight body and front - end structures , such as those constructed of advanced high - strength steel, composite - intensive, and magnesium . These assessments, either co mpleted or underway , include, for example, one in which the goal is to design, anal yz e, and develop the technology

for a composi te - intensive, body - in - white structure that achieve s a minimum of 60% weight savings over steel. Additionall y, the latest LM multi - material vehicle (MMV) project aims to sy nthesize and demonstrate these various lightweight material component options in a si ngle vehicle. Cost remains one of the major obstacles to successful market penetration of thes e various lightweight materials. Complete vehicle sy stem - level cost estimation is essential since it captures the cost reduction potential due to both part integr ation and mass de - compounding effect. Today OEMs remain more focused on the vehicle ’s retail price rather than on vehicle life cycle cost .2

This paper provides an assessment of the cost - effectiveness of a 40 % bod y and chassis weight - reduction goal for FY20 0 9 . The c ost - effectiveness of the proposed weight reduction goal is determined based on the vehicle retail and life cycle cost anal ys i s of a potential lightweight material substitution scenario in various body and chassis components to achieve the desired w eight - reduction goal . Cost methodology and potential data sources for the anal ys is are then discussed. Cost data collected for various vehicle components considered for achieving the weight reduction goal are then discussed , as are the assumptions and meth odology used. A discussion of the r esults of the cost anal ys is of the proposed scenario is then presented, followed b y conclusions . **2. Approach**  **2.1 Scenario Development**  Cost - effec tiveness of a 40 % body and chassis weight - reduction goal w as demonstrat ed based on a scenario anal ysi s by focusing on a specific lightweight material ty pe substitution at a major vehicle - component level . A representative mid - size vehicle , i.e. Honda Accord , was considered as the baseline against which the cost - effectiveness o f weight reduction goal w as determined . Due to a significantly higher weight reduction goal, carbon fiber - reinforced pol ym er - matrix composites ( carbon - FRPMCs) and aluminum w ere primaril y considered for body and chassis applications . These two materials hav e the potential to achieve the desired weight - reduction goal . Only c arbon FRPMCs offer the potential for greater than 50% reduction in the weight of body and chassis components while providing strength five times greater than steel for structural parts. Mo st applications of this material have been in high - end vehicles and race cars. Aluminum use in today ’s light - duty vehicles is limited to about 325 lbs/vehicle , mainly in castings for the powertrain (engine block, cylinder head and transmission cases) and wheels, but aluminum use could be significantl y greater with the addition of wrought aluminum that has a w eight reduction potential range of 30 - 50% compared to conventional steel . Table 1 shows the 40 % body and chassis weight - reduction scenario for a mid - size passenger car considered in the cost - effectiveness anal ys is . The scenario focuses on a plausible specific lightweight material option (i.e., mainly carbon - FRPMC or aluminum) at the broad component category level based on its near - term market potential to achieve the desired overall bod y and chassis weight reduction goal . T his scenario approach allows determination of cost - effectiveness at a vehicle level, the context important for the actual implementation and commercialization of the lightweighting ma terials technologies in the market place. Specific components considered under body and chassis vehicle subs ys tems are highlighted in Table 1 (in bold ty pe) . The potential weight reduction for each part also is given. Since most lightweight component optio ns considered here are ye t to be commercialized, the percentage weight reduction assumed in each case is based on the best estimated value available in the literature today . T he definition s of various vehicle components are based on the Automotive System C ost Model (ASCM , discussed below) and are provided in Appendix A.3 **Table 1. Mid**  **- Size**  **40 % Body& Chassis Weight Reduction Scenario**  **1 SYSTEM**  **Baseline 40% Weight Reduction Scenario**  **Technology Ma**  **ss**

**(kg) Technology**  **Ma ss**  **(kg) Pow**  **ertrain** Engine V - 6 3.0L DOHC AL/AL 197 V - 6 3.0L DOHC AL/AL 192 Energy Storage Lead - Acid, Standard 19 Lead - Acid, Standard 18 Fuel System Gasoline, 17 gal 83 Gasoline, 17 gal 83 Transmission Automatic (L5) 81 Automatic (L5) 79 P/T Thermal Generic (car) 29 Generic (car) 29 Driv eshaft/Axle Generic 77 Generic 74 Differential Generic 25 Generic 25 Ex haust System Generic 48 Generic 48 Oil and Grease Generic 15 Generic 15 Powertrain Electronics Generic 10 Generic 10 Emission Control Electronics Generic 10 Generic 10 **Bod y**  B ody - in -Wh ite Midsize steel unibody 320 **Carbon Fiber Poly mer Composites (55%** **wt redn.) 144** 

Panels Stamped Steel 60 **Carbon Fiber Poly mer Composites (55%** **wt redn.) 27**  Front/Rear Bumpers Sheet Steel 10 **TP/Carbon Fiber (60% wt reduction)**  **4**

Glass Conventional , 4 mm 40 **Poly carbonate (25%** **reduction) 30**  Paint Solventborne, avg color 12 Solventborne, avg color 12 Exterior Trim Generic 10 **ULSAB (35% wt. reduction) 7**  Body Hardware Generic 10 Generic 10 Body Sealers and Deadners Generic 2 Generic 2 **Chassis** Cradle Generic 35 **Aluminum (45% wt. reduction)**  **19** Corner Suspension Generic 47 **Aluminum (35% wt. reduction)**  **31** Braking System ABS 48 **Aluminum (5.5% wt reduction)**  **45** Wh eels and Tires Aluminum 15” 71 **Magnesium 15" (40%** **wt. reduction) 59**  Steering System G eneric 27 **Aluminum (5.5% wt. reduction)**  **26 Interior**  Instrument Panel Generic 26 Generic 26 Trim and Insulation Generic 24 Generic 24 Door Modules Generic 28 Generic 28 Seating and Restraints Generic 66 Generic 66

HVAC Generic 22 Generic 22 **Elect rical**  33 33 **Final Assembly** 40 40 **Total Body**

**& Chassis Weight**  (% less than baseline) 692 415 (40%) **Total Vehicle Weight 1525**  **1237**

1 All weights in the table denote values afte r primary weight savings only .4

**2.1. 1**  **Carbon -**  **FRPMC** Application of c arbon - FRPMC in automobiles is quite limited and occurs only in low volume nic he vehicles today such as Formula 1 race cars, Mercedes - Benz McLaren SL R supercar, Mazda’s RX - 8, Honda’s Legend sedan, Mitsubishi’s Pajero SUV, and Nissan’s latest GT - R super sports car. General Motors is using the Corvette ZR1 to study the feasibility of high - volume carbon - FRPMC parts, whereas Toy ota is planning to use a body frame made of this material in its 1/X concept car that will offer the same interior space as the Prius hy

brid but only

weigh one - third as much. Most carbon - FRP MC applications include drive shafts, spoilers, A - pillars, underbody structures, and various body panels for high - performance, low - volume cars. Three Japanese companies, i.e., Toray Industrie s, Teijin, and Mitsubishi Rayon, which control 70% of the global carbon fiber market, ar e aiming to pioneer mass production of this material for widespread use in cars. For example, Teijin who is planning to start supplying carbon - resin composites to automotive parts makers as earl y as 2010 via its subsidiary Toho Tenax, is aiming to first make engine undercovers for high - range sports cars and then move towards mass market models. Toray

Industries has invested in a German developer of carbon - FRPMC parts for cars and trucks, and is planning to expand its sales for automotive applications to app roximately

$510 million by

2015 , including ultimately mass - produce carbon - fiber parts mainly for Toy ota . Honda and Nissan have similarly joined with Toray

and Mitsubishi Rayon to research new, less - expensive carbon fiber for cars. To achieve a significant ly higher body

and chassis weight reduction goal, this analy sis considers carbon - FRPMC for three major bod y components as shown in Table 1. These three bod y components, b ody - in - White (BIW) , panels, and front/rear, have been considered as the most suitable components application of this lightweight material since these components contribute more than 25% of total vehicle weight. Potential percentage weight reduction assumed for these components has been in the mid range of 55 - 60%, although expected weight re duction has been reported to be 45 - 80% compared to mild steel depending on specific automotive part application. For example, Focal Project 3 of the Automotive Composites Consortium (ACC)

— a collaborative, pre - competitive R&D partnership of the three big OE Ms and DOE

— predicted a 66% BIW weight reduction with a total number of parts less than 20 by demonstrating the potential on a carbon fiber B - pillar (Iobst et al. 2007) . Similarly , niche vehicles such as X - Power sports vehicles have demonstrated 70% weight reduction potential in body panels compared with steel (Marsh 2006) . On the other hand, the structural composite underbody targeted to be a part of the United States Automotive Material Partnership (USAMP) Multi - Material Vehicle (MMV) project has obtained only 29% weight reduction using carbon fabric for floors . T he project’s objective , however, was to capitalize on the material’s strength to optimize the crash performance rather than to reduce weight (Berger and Jaranson 2009). In fact, carbon - FRP MC is cur

rently not under further consideration in the MMV project and a new project on carbon - FRPMC body structure to optimize the weight savings potential has been under consideration for near - term fund i ng . Use of carbon fibers in Formula 1 cars such as Mercedes McLaren SLR in monocoque design is 50% lighter than steel components (Marsh 2006) , and a 48% reduction in BIW mass without doors has been5

considered for a composite monocoque using various combinations of carbon and glass fibers in one of the earlier studi es (Mascarin et al. 1995). **2.1. 2**  **Aluminum** To achieve the desired 40% body and chassis weight reduction goal, aluminum substitution was considered in several vehicle chassis components , as shown in Table 1 , including c orner suspension, cradle , braking sy stem, and steering s ys tem . Aluminum (forged or cast) is desirable in vehicle chassis components because it reduces un - sprung weight of the suspension, thereb y improving overall handling performance and ride comfort. The cradle is the component assumed to hav e the most weight reduction

— 45%

— among the components considered here for aluminum substitution . Aluminum penetration has been relatively high in steering knuckles , and a weight reduction in the range of 35 - 45% can be achieved b y integrating multiple parts into a single unit. Simi larly , aluminum control arms, with a weight reduction potential of 20 - 30% compared to steel, have a 20% market share today . Aluminum corner suspension substitution assumes here both aluminum control arms and steering knuckles , w ith a combined weight reduction potential 35%. Aluminum use has been considered for brake actuators and steering wheel column, with an estimated weight savings potential of 30.5% and 43%, respectively (EEA 2007) . However, in both cases, the substitution o f a single component in the s ys tem achieves a relativel y small weight reduction at the system level compared to the weight reduction achieved in the single part. The weight reduction potential in e ach sy stem is assumed to be 5.5%. Although the wheels segme nt has seen consistent growth in aluminum use , it is anticipated that the more aggressive weight reduction goal will produce a shift from cast aluminum wheels to cast magnesium wheels , the latter offering a 40% weight reduction potential compared to cast a luminum wheels (EEA 2007) . Li ke other lightwe ight materials, high production - volume cost has been the limiting factor that historically limited automotive growth. To date, an average vehicle contains 10 - 12 lbs of magnesium, mostly as castings in the instrument panel beam, transfer case, steering components, and radiator support. There is a great need for development of wrought magnesium products and manufacturing processes to provide improved mechanical and phy sical properties, crash performance, and corros ion resistance before magnesium’s use in more critical body and chassis applications can be expanded. T o achieve the total savings goal of 40 % of the primary

body and chassis weight, a 3 5% reduction in exterior trim weight has been assumed . This weight sav ings are consistent with the target weight for the PNGV - Class vehicle which has a target weight of around 100 0 kg vehicle curb mass (ULSAB - AVC 1999). **2.1.3 Secondary Weight Savings**  The objective for the selection of lightweighting material options for v arious vehicle components (as discussed above) was to achieve the primary 40 % bod y and chassis weight - reduction goal . However, consideration of s econdary weight savings in body

and chassis components is important because it takes into account the effect of primary6

savings on the powertrain, chassis, and body components . The c ost - effectiveness of l ightweighting options depends considerably on the secondary savings since those savings helps to reduce the overall effect of higher lightweight material cost. Pow ertrain resizing in secondary

weight savings calculations allow s comparisons of functionally equivalent vehicle designs

— a reduced vehicle weight require s a less powerful engine to achieve equivalent performance (i.e., acceleration, range etc.). Secondary w eight savings have been estimated b y ASCM , and those savings related to the two scenarios considered here are presented i n Table 2 along with other estimated major parameters in the cost effectiveness anal ys is. Total secondary weight savings are estimated to be 49 % of primary savings and depend on the number of vehicle components considered . M ost of the secondary

weight savings o ccur in the powertrain sy stem and depend on the extent o f powertrain downsizing assumed . Since the ASCM includes secondary weight savings only of major vehicle components (i.e., all chassis components and a few major powertrain and bod y components) , the percentage total weight savings in this case is somewhat lower than another recent estimate (Malen and Redd y 2007).

**Not e:**  % values within parenthesis indicate savings with respect to baseline steel With the consideration of secondary weight savings, total body and chassis weight savings are estimated to be 45.3 % as shown in Table 2. There will be a decrease in powertrain weight with p o wertrain resizing, where engine power is estimated to decrease by 2 4%. The resulting vehicle weight reduction has been estimated to 28 %. Fuel econom y estimates have been based on a reasonable rule of thumb that each one percent reduction in weight should give a 0.66 percent improvement in fuel economy, after a vehicle has been full y redesigned to account for the reduced power demands of a lower mass. Combined vehicle fuel econo my would increase from the baseline value of 23 mpg to 2 7 . 2 mpg with the 40 % body and chassis weight - reduction goal. **Table 2. Major**  **Parameters Considered in the**  **Cost -**  **Effectiveness Analysis**  **of the**  **40% Body and Chassis Weight Reduction Goal Parameter**  **Baseline 40% Body and Chassis**  **Weight Reduction Scenario** Primary Body & Chassis Weight Savings NA 277 kg (40%) Secondary

Weight Saving s Bod y & Chassis NA 37 kg (5.3%) Powertrain NA 98 kg Total NA 135 kg Bod y & Chassis Weight 692 kg 378 kg (45%) Powertrain Weight 594 kg 485 kg (18%) Engine Power 122 kW 93 kW Final Vehicle Weight 1524 kg 1102 kg (28%) Combined Fuel Economy 23 mp g 27.2 mpg Vehicle Lifetime Operation 120,0007

**2.2 Cost Estimation Methodology**  As with the earlier stud y (Das 2008), this anal ys is employ s the Automotive Sy stem Cost Model (ASCM), dev eloped jointly by Oak Ridge National Laboratory and Ibis Associates, Inc. in collaboration with Argonne National L aboratory , to estimate the c ost effectiveness of the 40 % body and chassis weight - reduction goal . ASCM estimates the vehicle - manufacturing cost at a level of five major vehicle subs ys tems (powertrain, chassis, body , interior, and electrical) consisting of more than thirty - five components (some components have been shown in aggregate form in Table 1 before) based on the aggregation of several comp onents under the definition of Uniform Parts Grouping (UPG) generall y used b y the automotive industry (as listed and defined in Table 1 and Ap pendix A). E ach component represent s a specific manufacturing technology . Vehicle retail price based on the sum of manufacturing cost (i.e., costs of components and assembly) , overhead, and selling is added to vehicle operation costs for the vehicle life cy cle cost estimation. The interrelationships among vehicle subs ys tems and their effect on vehicle manufacturing co st are addressed, allowing inclu sion of the impacts of secondary mass and cost savings as well. Functional interrelationships have been developed for major chassis components to estimate secondary mass savings based on first principles of ph ys ics, and usin g semi - empirical and empirical information available from the literature today . The powertrain sizing routine in this model is based on the algorithm used in the Argonne National Laborat o ry ’s (ANL) hy brid vehicle cost model (HEVCOST), where the power and m ass projections of various powertrain components are based on component - specific power and efficiency values, with the capability to evaluate alternative h ybrid electric vehicle configurations and performance strategies (Plotkin et al. 2001). The main obje ctive of this model is to facilitate estimation of vehicle - manufacturing and life - cy cle costs using a uniform methodology to allow comparison of alternative advanced technologies being considered for vehicles today . This cost model has been integrated into the vehicle performance model PSAT (Powertrain S ys tem Analy sis Toolkit) developed by Argonne National Laboratory , thereb y facilitating instantaneous vehicle cost estimation based on the detailed powertrain component sizing estimates by PSAT. This cost mod el has been used in several studies for a comparative cost assessment of different powertrain and body - in - white options for advanced technology

vehicles (Das 2004 and 2005; Rousseau et al. 2005) . Two ty pes of overhead, i.e., OEM and dealer margin are adde d to the vehicle manufacturing cost to estimate vehicle retail price . The former is assumed to be fixed, while the latter varied with the vehicle manufacturing cost. Vehicle operation cost categories considered in the vehicle life cycle cost estimation inc lude financing, insurance, local fees, fuel, battery replacement, maintenance, repair, and disposal. Financing, insurance, and local fees cost s are dictated b y the vehicle retail price, while the fuel cost is dictated by the vehicle’s fuel economy ( estimat es are shown in Table 2 ) and a gas oline price of $ 1.90 /gallon, based on near - term price trend s (EIA 2009) . With the exception of maintenance and repair, all other operation cost categories vary with the two lightweighting scenarios considered here based on estimated vehicle retail price and fuel econom y . Total life cycle cost is estimated as the net present value assuming total8

vehicle lifetime miles are 120,000

— based based on average 10,000 miles driven annuall y and a vehicle life of 12 years — and a discount rate of 10%. **2.3 Component Cost Data** Component technology cost data used in the anal ysis are mainly based on the latest estimates developed b y Ibis Associates, Inc. using results of the recent studies developed for the industry

(Ibis 2008 and Ibis 2009 a ). One such recent study stems from the US C A R - ACC composite structure programs that have been involved in the detailed cost anal ys is of c arbon - FRPMC body structures. Even detailed cost anal ys es can have limitations

— in this case the limitation is that the program never developed a complete design or high production - volume - scale cost analy sis for a full y functional BIW structure. Cost data for other components

—those for which the technology remained unchanged

— were the same as those in the original model, sin ce our objective in this anal ys is is to determine the relative cost - effectiveness of the plausible lightweight scenario to achieve the de s ired weight reduction goal and not the absolute total vehicle cost. Note that component technology costs in ASCM are b ased on OEM costs and represented in terms of functional relationships such as component mass and power, based on the detailed cost analy ses available in the literature. Several r ecent USCAR - ACC composite structure programs have been used in order to extr apolate to a full BIW structure and panel s ys tem functionally equivalent to the carbon fiber scenario considered previously in ASCM. The ACC programs contributing to this anal ys is include the FP2 - composite truck box, FP3 - carbon fiber structures, the Compos ite Underbod y program, and a recent fiber, pr e forming, and molding technology tradeoff study (Ibis 2007, 2009b; Berger and Jaranson 2009 and Boeman and Johnson (2002)) . The truck box study

evaluated a high volume composite design and process study employin g P4 preforming and SRIM molding. Similarly , the carbon fiber structures program demonstrated a 60% mass savings over steel for a molded carbon fiber composite, al though this wa s a large pillar t ype component and not a full vehicle structure. The Underbody program examined a broad range of concepts, including random and fabric glass, carbon, and high modulus poly prop yl ene (HMPP) reinforcement through sheet molding compound (SMC) c ompression, long - fiber injection (LFI), and direct long - fiber thermoplastic ( DLFT) molding processes. The most recent ACC tradeoff study compared glass, carbon, and natural fiber composites produced through SMC, structural reaction injection molding (SRIM), and resin transfer molding (RTM), and evaluated design based on equivalent strength and stiffness. Mass savings on individual components relative to steel ranged from 37% to 70% depending on the tensile or modulus equivalency . As noted earlier, a mass savings of 55% has been assumed in our case of carbon - FRPMC body structure, i.e ., BIW and panels. The production economics are based here on the recent studies using high production rate P4 preforming and SRIM molding, achieving producti on rates of 15 parts per hour. The carbon material pricing is based on current volume pricing esti mates of $30.80/kg ($14/lb), rather than the optimistic $22/kg ($10/lb) used in some of the earlier studies , and $4.24/kg for poly urethane s ys tems.9

The entire bod y structure and carbon SMC panel systems were modeled using IBIS Technical Cost Models and th e new regression analy ses have been conducted to establish updated cost relationships sensitive to production volume, mass, material price, piece count, and part area. Figure 1 shows the estimated cost sensitivity to annual production volume of carbon - FRPM C body - in - wh ite structures for a mid - size vehicle . Estimated costs are based on the baseline BIW and panel mass of 128 kg and 42 kg, respective ly , representing a 49% reduction in mass compared to the baseline steel body structures . As one would expect, car

bon - FRPMC body

structure is quite in sensitive to annual production volume since it is a low - volume process : total part cost varies less than $20/part and is relativel y constant at around $ 2 , 960 /part bey ond production volume of 50,000 parts/y ear . The cost sensitivity

to annual production volume f o r bo dy - in - white structure s of various materials is shown in Figure 2 . The costs represented in Figure 2 include the assembl y cost. Cost graphs shown here are based on the baseline weight for a mid - size vehicle cons idered in the model and not the actual weight used in the anal ys is here. For example, baseline mass es of bod y - in - white structure considered for steel, aluminum, and thermoset/glass composites (TS/glass composites) are 250 kg, 143 kg, and 202 kg, respective ly . C urrent material pricing is as follows: steel $0. 77 /kg ; aluminum sheet $3.31/kg; aluminum casting $2. 86 /kg ; v inyl e ster compound $4.24/kg; gl ass fiber $1.50/kg ; and carbon fiber $30.80/kg ( reflecting a recent surge in demand for large commercial jet ai rcrafts) . Based on these material prices and masses assumed, the carbon FRPMC structure is more expensive than all other lightweight material options considered here , except at annual production volume of 10,000 parts, when the aluminum unibody is more exp ensive than carbon - FRPMC . The crossover between these two materials is estimated to occur between production volume s of 10K - 25K . Unlike the current estimate, m ost past studies indicate cost parity of carbon - FRPMC with conventional baseline steel structure at a production volume in the range of 5,000 - 35,000 (Kang 1998 and Fuchs 20 0 8 ). Their estimates of cost parity are mainly

due to their assumption of l ower carbon fiber price s of $11 - $17.50/kg , compared to this anal ys is’ assumption of $30.80/kg . Fuchs (2008 ) estimated cross - over point of 35,000 f or the cost effectiveness of traditional steel and carbon composites represents 45 % of car models and 10 % of all cars produced in North America in 2005. The cost sensitivities of steel and aluminum structure s are qui te similar to each other in terms of the curve slope, but they are offset by

the material price difference and some increased processing costs. As also has been observed earlier, the cost sensitivity curve s for composite bod y structures (i.e., for both gl a ss - FRPMC and carbon - FRPMC) are relatively flat compared to other materials. For our analy sis, the threshold production volume of cost - effectiveness is 240K parts/y ear for baseline steel and 5 0K parts/year for the lightweight vehicle.10 0 500 1000 1500 2000 2500 3000 3500 4000

0 50 100 150 200 250 300 **An nua**  **l Pr oduc**  **ti on V**  **olum e**  **(K )** **C a** **r b** **o n** **- F** **R P** **M C** **B o** **d y** **S t** **r u** **c t** **u r** **e C** **o s** **t (** **$ /** **p a** **r t** **)**

St ru ctu re Asse mbly Pa nel s To ta l

**Figure 1. Carbon**  **- F**  **RPMC Body**  **Structure Cost Sensitivity to** 

**Annual Production Volume**

0 500 1000 1500 2000 2500 3000

0 50 100 150 200 250 300 **Annua l Pr**  **oduc ti**  **on V olum**  **e (K**  **) B** **o d** **y -** **i n** **- W** **h i** **t e** **S t** **r u** **c t** **u r** **e C** **o s** **t (** **$ /** **p a** **r t** **)**

St eel U ni bo dy Al uminum U ni bo dy TS /G lass Co mpo site CF Co mpo site **Figure 2.**  **Lightweight Material Body -**  **In -**  **White Cost Sensitivity to**

**Annual Production Volume**11 0 100 200 300 400 500 600

0.5 1 1.5 2 2. 5 3 3.5 4 4.5 **Al C**  **asting Price ($/kg)** **P a** **r t** **C o** **s t** **( $** **)** Br ak e Syste m Ste eri ng Syste m Cradle Corner Su sp ens io n

Ba sePrice $ 2.86/kg **Figure 3. Aluminum Chassis Component Cost Sensitivity to Material Price** Figure 3 shows the p er - part cost sensitivity to aluminum casting price for four different aluminum chassis components considered under the carbon - FRPMC scenario based on part weight used in a mid - size vehicle. Note that the part cost estimates for the base price of $2.86/kg f

or aluminum casting is also shown. The cost estimates for the aluminum cradle include s not only

casting cost, but also melting, scrap recovery , machining, and corrosion protection. Cost estimates of aluminum braking and steering s ys tems were made b y adding the estimated cost of replaced aluminum component (e.g., brake actuators and steering wheel column for braking and steering s ys tems, respectivel y) to the unchanged original balance of s ys tem cost made of conventional steel . Cost data for replaced aluminum components are based on recent available estimate s (EEA 2007). Cost relationships consist of two components, i.e., material and processing. A s Figure 3 shows , the h igher weight of the corner suspension causes its cost to be higher and more sensitive than the cradle is to aluminum ingot prices . The sensitivity of steering and braking sy stem cost s to aluminum ingot pricing is not significant since the aluminum component s c ontributes less than 10% of total sy stem weight in each case . Cost of cast magnesium wh eels are based on 15” wheels and reflects current material pricing and processing technology

improvements and also includes tire costs. Ithas been assumed to have 20% price premium compared to cast aluminum wheels (EEA 2007 and Long et al. 2005 ). **3.0 Re sults**  Figure 4 shows the estimated cost savings resulting from the 40% bod y and chassis weight savings of the carbon - FRPMC scenario compared to the baseline, by major vehicle s ys tems, vehicle retail price , and life cy cle cost . Only three major vehicle s ys tems12 **-2 500**  **-2 000**  **-1 500**  **-1 000**  **-5 00**  **0 500**  **1000 1500** 

**1 C** **o s** **t S** **a v** **i n** **g s** **( $** **/ v** **e h** **i c** **l e** **)** Po w e rt ra in Body Ch as si s Ve hic le R

etail P ri ce Op er ation Li fe C ycl e C os t

**Figure 4. Estimated Cost Savings of 40% Body and Chassis**

**Weight Reduction Scenario** are considered because the cost of other vehicle sy stems

— interior, electrical, and final assembly

— are assumed to be the same under all scenarios. There would be $1 490/vehicle increase in retail price level and a $1100/vehicle increase in life cycle cost. The increase in vehicle retail price is mainly due to the body

s ys tem cost increase of about $ 22 00 , the result of the higher cost of carbon unibody structure. The c ost savings due to the downsizing of the powertrain and chassis is not sufficient to lower the vehicle retail price. In addition, with the consideration of quite a few operation cost categories (e.g., financing, insurance, and local fees) a s functions of v ehicle retail price and the assumption of lower gasoline price of $1.90/gallon

– a 40% weight reduction goal cannot be achieved even at the level of life cy cle cost. Itis estimated that if the price of aluminum used in chassis components is reduced from the baselin e price of $ 2.86 /kg to $2. 20 /kg and carbon fiber price is reduced from the baseline price of $30.40/kg to DOE ’s long - term target value of $6.60/kg , the cost - effectiveness at the life cycle cost level could be achiev ed, even at the assumed gasolin e price of $1.90/gallon. As one would expect, the cost - effectiveness of carbon - FRPMC vehicle would improve with higher fuel price as also shown here in Figure 5. It is estimated that if the fuel price increased from a baseline price of $1.90/gallon to about $4.25/gallon, cost - effectiveness could be achieved at the level of vehicle life cycle cost without requiring any material price reductions . It is anticipated that a combination of material price decrease s and a fuel price increase would be necessary

to a chieve the cost - effectiveness of carbon - FRPMC vehicle at the level of vehicle retail price .13 40000 42000 44000 46000 48000 50000 52000

1 1. 5 2 2. 5 3 3. 5 4 4. 5 5 **Fue l Pr**  **ic e (**  **$/ ga**  **llo n)** **L i** **f e** **C y** **c l** **e C** **o s** **t (** **$ /** **V e** **h i** **c l** **e )** 

Bas eline Ste el Carbon-F RPM C

**Figure 5. Vehicle Life Cycle Cost Sensitivity to Fuel Price**  **4.0 Conclusions** Cost - effectiveness of ALM’s 200 9 body and chassis weight reduction goal of 40 % in light - duty vehicles was assessed based on the use of lightweight material options for various body

and chassis components under a plausible mid - size vehicle scenario. The weight reduction goal here is very similar to that of the Japanese government wh os e intention is to mass - produce a cost - effective, recyclable carbon fiber and use it to achieve a 40% reduction in cars by the middle of the next decade (Brooke 2009). The l ightweight material substitution options considered here focused on carbon - FRPMC f or body sy stem s and aluminum for chassis components. Among potential lightweighting materials, carbon - FRPMC has the greatest weight savings potential . The analy sis also considers the e ffect of primary weight savings of 40 % on other vehicle components that can be resized while maintaining th e same level of vehicle performance with the reduced vehicle weight . This weight savings are known as secondary weight savings. Due to consideration of secondary weight savings, total body and chassis weight savings are e stimated to be 45 %, whereas the final vehicle weight savings of 28 %. Cost - effectiveness of 40 % bod y and chassis weight reduction goal is estimated in terms of both vehicle retail price and life cycle cost using the detailed 35+ component level automotive s ys tem cost model developed b y OR

NLand Ibis Associates, Inc. Cost data of components considered14

for lightweight material substitution are collected from recent major studies, thereb y reflecting the latest technology developments and material prices. Even with the consideration of powertrain resizing and secondary body and chassis mass savings , carbon - FRPMC lightweight material vehicle option i s not cost - effective in meeting the ALM 40 % body and chassis weight savings goal from the life cycle cost perspecti ve if the recent low gasoline price trend continues . The h igher cost results mainly from using the carbon - FRPMC body s ys tem which is $2200 more expensive than the baseline s ys tem. T he higher cost is not offset during the vehicle operation stage. The h igher vehicle retail price also affects some of the operation cost categories such as financing, insurance, and local fees which are functions of vehicle retail price. The vehicle retail price is estimated to be $1492 higher than baseline. The life cycle cost i s $1102 higher. From the life cycle cost perspective, either a change in material price or fuel price would be necessary to achieve the cost - effectiveness goal. Aluminum and carbon fiber prices need to be at $2.20/kg and $6.60/kg, respectivel y, where as fue l price needs to be $4.25/gallon for the lightweight vehicle to be cost effective . I t is likely that a combination of material and fuel prices would be necessary to achieve the cost effectiveness at the level of vehicle retail price , which is the primary c onsideration of OEMs for determining the viability of an y new vehicle technology . The extent of the necessary price changes would depend on the extent of secondary mass savings considered, with this analy sis employing a conservative estimate of secondary m ass savings. In contrast to this conservative estimate, General Motors 1992 Ultralite carbon body structure weigh 191 kg (compared to the 171 kg body structure in this anal ys is ) demonstrated a super - lean 635 kg curb weight concept car

— considerabl y lower th an our estimated curb weight of 1102 kg. Findings in this anal ys is are consistent with the earlier findings that carbon - FRPMC is too expensive for large scale application in light - duty vehicles today . Composite monocoque BIW designs considered in the pas t several studies indicate cost to be in the range of 41 - 73% higher than the steel unibod y, depending on the t yp e of tooling used (Mascarin et al. 1995). The technology is suited for mainly

low annual production volume , and a reduction in carbon fiber pric e would help to a large extent in improving its viability . Vehicle platforming considerations which allow low annual production volume s would facilitate the competitiveness of carbon - FRPMC body structure (Fuchs et al. 2008). Li ghtweighting also improves th e cost - effectiveness of advanced technology vehicles b y lowering the expensive powertrain cost while maintaining the performance (Aluminum Assoc i ation 2008, Brooke 2009, and Das 2005). Consideration of powertrain resizing, secondary

mass savings, and life cy cle cost perspectives would therefore be important to maximize the fuel economy gains from a lightweight structure and eventual successful market penetration of lightweight vehicles in the future. With a higher lightweighting goal, reduced material cost become more critical because it is such a large share of the total part costs particularl y in low production volume production manufacturing processes . Accordingl y, a current focus of DOE ’s lightweight materials program is the development low cost carbon f ibers from alternative cheap renewable resources and high - volume processing of composit es.15 **REFERENCES** Aluminum Association (2008). “Aluminum Vehicle Structure: Manufacturing and Lifecycle Cost Analy sis: Hy brid Drive and Diesel Fuel Vehicles,” Research Re port No. 2008 - 05, written b y Ibis Associates, Inc. for the Aluminum Association. Berger, L. and Jaranson, J. (2009). “Automotive Composites Consortium Focal Project 4,” FY 2007 Progress Report for Lightweighting Materials, Vehicle Technologies Program, U. S. Department of Energy , Washington, DC, Available at: http://www1.eere.energy .gov/vehiclesandfuels/resources/vt_lm_fy 07.html , accessed on 5/22. Boeman, R. G. Johnson, N. L(2002). “Development of a Cost Competitive, Composite Intensive, Bod y - In - White,” SAE Paper No. 2002 - 01 - 1905, the Society of Automotive Engineers, Warrendale, PA. Brooke, L. (2009). “ A Featherweight Future, ” Automotive Engineering International, Vol. 117, No. 5, May , pp. 24 - 26 Das, S. (2004). “A Comparative Assessment of Alternative P owertrians and Bod y - in White Materials for Advanced Technology Vehicles,” SAE Paper No. 2004 - 01 - 0573, the Society

of Automotive Engineers, Warrendale, PA. Das, S. (2005). “Lightweight Opportunities for Fuel Cell Vehicles,” SAE paper no. 2005 - 01 - 0007 , the Society

of Automotive Engineers, Warrendale, PA. Das, S. (2008). “Cost - Effectiveness of a 25% Body and Chassis Weight - Reduction Goal in L ight - Dut y Vehicles,” draft report, Oak Ridge National Laboratory, Oak Ridge, TN, Aug. Energy and Environmental Anal ys is, Inc. (EEA) (2007). “Anal ys is of Light - Duty Vehicle Weight Reduction Potential,” draft final report submitted to the U.S. Department of Energy , Office of Policy , Arlington, VA, July . Energy Information Administration (EIA) (2009). “Annual Energy Outloo k 2009 with Projections to 2030, Updated Annual Energy Outlook 2009 Reference Case with ARRA, http://www.eia.doe.gov/oiaf/servicerpt/stimulus/excel/aeostimtab_12.xls accessed on 5/28/09 . Fuchs, E. R. H. Field, F. R. Roth, R. and Kirchain, R. E. (2008). “S trategic Materials Selection in the Automobile Bod y: Economic Opportunities for Poly mer Composite Design,” Composites Science and Technology , Vol. 68, pp. 1989 - 2002. Ibis Associates, Inc. (Ibis) (2007). “Technical Cost Model Development for a Structural Composite Underbody : Supporting USCAR - ACC Composite Structures Program,” Waltham, MA.16

Ibis Associates, Inc. (Ibis) (2008). “Data Document: ORNLAutomotive Sy stem Cost Model,” Waltham, MA, July 1. Ibis Associates, Inc. (Ibis) (2009 a ). “Data Document: OR NLAutomotive Sy stem Cost Model,” Waltham, MA, April 9. Ibis Associates, Inc. (Ibis) (2009b). “Technical Cost Analy sis & Model Development: Fiber and Process Preforming Alternatives: Supporting USCAR - ACC Composite Structures Program, ” Waltham, MA. Iobst , S. Berger, L. Fernholz, K. Dahl, J. and Smith G. (2007). “Fabrication of the Automotive Composites Consortium Carbon Fiber B - Pillar,”International SAMPE Sy mposium and Exhibition (Proceedings), v 52, SAMPE’07: M and P

– From Coast to Coast and Around the World, Conference Proceedings, 2007, 11p. Long, S. Xu, S. and Cao, H. (200 5 ). “Technical Economic Considerations for Production and Application of Mg Castings in China,” Materials Science Forum, Vols. 488 - 489, pp. 909 - 914, June. Malen, D. E. and Redd y, K . (2007). “Preliminary Vehicle Mass Estimation Using Empirical Subsy stem Influence Coefficients,” report prepared for the FGPC Mass Compounding Project Team, Auto/Steel Partnership, Southfield, MI , May 9. Marsh, G. (2006). “Composites Conquer with Carbon Supercars,” Reinforced Plastics, Jan., pp. 20 - 24. Mascarin, A. E., Dieffenbach, J. R. Brylawski, M. M. Cramer, D. R. and A. B. Lovins (1995). “ Costing the Ultralight in Volume Production: Can Advanced Composite Bodies - In - White Be Affordable?,” paper pres ented at the 1995 International Bod y Engineering Conference & Exposition, held on Oct. in Detroit, MI . Plotkin, S. et al. (2001). “Hy brid Vehicle Technology

Assessment: Methodology , Analy tical Issues, and Interim Results,” Argo nne National Laboratory Repo rt ANL/ESD/02 - 2, Argonne, IL. Rousseau, A. Sharer, P. and Das, S. (2005). “Trade - off between Fuel Economy and Cost for Advanced Vehicle Configurations,” presented and published at EVS21conference, held in Monaco, Apr. 2 - 5. Ultra light Steel Autobody

– Advanced Vehic le Concepts (ULSAB - AVC) (1999). “Description of UL SAB - AVC Benchmarking and Target Setting,” Southfield , MI . Nov. 18.17 

### Appendix A **ASCM Vehicle Component Definit**  **i on**  **ASCM UPG**  **ASCM Description**

**Group Name**  **Pow ertrain**  Engine 30A Base Engine In this model, 'engine' refers to conventional heat engines. In addition to basic powerplant and auxiliary systems and components, engine cooling systems, lubrication, fluid containers and pumps are also included. 30B Other Engine

Components Fuel C ell n/a Fuel Cell Power System Generator n/a The APU or power converter for parallel and series hybrids. Motor n/a The electric motor, including power cables. Controller/ Inverter n/a The power controller/phase inverter system Energy Storage 36 K01 High Voltage Battery The primary electrical energy storage device or package.

Ma ybe a single battery or module of linked cells. Fuel System 36F Fuel Tank and Lines Fuel tank, gauge, tank shield, access door, mounting

straps, fuel pump. 37B Fuel Transmission 36E G Transmission In this model the transmission refers to the gearbox only. Note that in some literature, "transmission" refers to the clutch, gearbox, driveshaft, and differential. These are each treated as separate components/subsy stems in this model. 36C Clutch and

Controls Supplied as a single assembly, a releasable coupling that

transmits torque from the engine to gearbox. Driveshaft/ Ax le 31 Final Drive A single assembly that couples with the gearbox and differential 31 Final Drive An assembly of the axle shaft, housing, boots, and couplings to the wheels Differential 31 Final Drive Transmits energy from driveshaft to axles and allows for differential speed of each wheel. P/T Thermal Cooling module (radiator, fan assembly etc) Ex haust System 36E

36O Ex haust System

Catalytic Converter All exhaust equipment after the manifold; pipe: catalytic

converter, muffler. Powertrain Electrical 30C Engine Electrical Engine control wiring, sensors and processors. The con troller for electric motors for HEVs may be considered as part of the electric motor, or could be included here, if desired. Low voltage used for accessory power is also included here. Emission Control Electronics 30C10 Engine Emission Controls The sens ors, processors, and engine feedback

equipment that maintain emissions within specified parameters. Oil and Grease 37B Oil and Grease Engine oil, transmission oil, miscellaneous lubricants18 **ASCM UPG**  **ASCM Description**

**Group Name**  **Bod y**  B IW 11A - 11B Body in W hite and closures The Body - In -Wh ite is the primary vehicle structure,

usually a single - body assembly, consisting of engine compartment, passenger cabin, and storage. Closure panels (including hinge mechanism) and hang - on panels (such as fenders) are included, even if non - structural. In thi s model, doors are included as well. Front/Rear Bumper 36G Fenders Glass 18 Glass Front and rear windshields, door window glazing Paint 22 Paint and Coating Includes the cost and mass of the total painting operation; e - coat, priming, base coats, color coats, clear coats. 37A, C, D Paint Exterior Trim 14, 20 Molding and Ornaments Bumper cover, air deflectors, ground effects, side trim,

mirror assemblies, nameplates Body Hardware Door window mechanism, wipe/wash, defog/deice, door latch me chanism Body Sealers & Deadeners Self - explanatory **Chassis** Cradle 32 Frame A front sub frame that bolts to the BIW and supports the mounting of the engine Corner Suspension 33 Suspension Upper and lower control arms, ball joints, spring, shock absor ber, steering knuckle, stabilizer shaft Braking System 35 35D Brakes Hub, disc, bearings, splash shield, and calipers. Wh eels and Tires 36A 36C Wh eels, Tires, and Tools Self explanatory. Tools determinant by type of tires

featured. Steering System 3 4 Steering A complex system from the steering wheel, column, joints, linkages, bushes, housings and potentially hydraulic or electric assist equipment. **Interior** Instrument

Panel 21 Trim and Insulation The instrument panel module consists of an underlying

panel structure, knee bolsters and brackets, the instrument cluster, exterior surface, wiring, console storage, glove box panels, glove box assembly and exterior, and a top cover. Trim and Insulation 15,17,21 Headliner Headliner is actually the overhead system containing acoustical sound absorption, assist handles, coat hooks, modular headliner assemblies, overhead console assemblies, small item overhead storage, pillar trim, sun visors and retainer. Center Console Emergency brake cover, switch panels , ash trays, arm

rest, cup holders, sometimes grouped with seating. Package Tray A molded or formed panel behind the rear seat,

sometimes contains accessory brake light. Carpeting/Flooring Acoustical sound absorption; padding and carpet,

insulation and accessory mats sometimes flooring may be sold as part of a combined acoustic package, also involving other sound abatement components, such as wheel well liners and under hood insulation Door Modules 19 Convenience Items A door panel system containi ng door insulation, door trim

assemblies/panels, map pocket trim, cup holders, ash trays, seatbelt retractor covers, speaker grills, armrests, switch panels and handles Seatbelt & Restraints 16 Seats The seating system contains seat tracks, seat frames, foam, trim, map pockets, restraint anchors, head restraint,19 **ASCM UPG**  **ASCM Description**

**Group Name**  and armrests. 81 Safety Equipment Seat belts, tensioners, clips, air bags and sensors assemblies HVAC 80A, B Air Conditioning System Condenser, heater, ducting, and controls, compressor

and A /C hardware. 80H, J Heating System 80K, M, C Other Climate

Control **Electrical** Interior

Electrical 12F - 13, 79 Electrical Components Wi ring and controls for interior lighting, instrumentation,

and power accessories, entertainment system. 85 Acces sories

Equipment Chassis Electrical 36K Chassis Electrical ABS electrical system (wiring, sensors, processors), traction control Exterior Electrical 14,20 Molding and Ornaments Head lamps, fog lamps, turn signals, side markers, tail

light assemblies **Final Assembly**  Interior

Chassis Powertrain Electronics Other Systems Final assembly of vehicle components is represented at the level of five major vehicle subsystems under which components are grouped