Volvo Powertrain North America,a division of Mack Trucks, Inc.Supplement to Request for Reduced Maintenance Interval, US10 SCR1REDACTED VERSIONMr. Karl SimonDirector, Compliance and Innovative Strategies DivisionUS Environmental Protection Agency1310 L Street NWWashington, DC, 20005Dear Mr. Simon:This supplement to Volvo Powertrain’s submittal, Volvo Powertrain Request for Administrator Approval of New MaintenanceIntervals: Refillof Diesel Exhaust Fluid Tanks Utilized with HDOH SCR-Based Emissions Control Systems, June 29, 2009,is intended to offer supplementary information with respect to the minimum maintenance interval requirements associatedwith SCR Diesel Exhaust Fluid refill.Regulated emissions intervals of 150,000 miles / 4,500 hrs would roughly equate to a DEF tank size of over 900 gallons for acommon highway vehicle with fuel capacity of 200 gals and achieving 6.5 miles per gallon fuel efficiency. A DEF tank ofthis size is terribly irrational if not impossible to package on a modern vehicle. When full with DEF, such a tank wouldweigh well over 8500 lbs, which represents a grossly significant impact to total cargo capacity and vehicle axle weights.Vehicle fuel efficiency would be impacted as well, carryingthis significant additional weight outside the revenue bearingcargo weight, which translates to higher CO2 emissions for eachton-mile transported. Based on these simple estimationsand observations, the need to have a reduced interval for DEF refill is more than obvious.When considering more frequent intervals, there are various critical factors that must be considered. To avoid extensiveredesign of the vehicle, tank sizesmuchsmaller than that which provides a 150,000 mile interval must be considered. Infact, DEF tank sizes resulting in DEF/fuel refill ratios inthe range of 2:1 or 3:1 can have significant vehicle redesignimplications. This means that establishing the minimum tank size and associated ratio requires that chassis designimpacts, including total cost, weight and vehicle length, mustbe limited to a level that minimizes the customer impacts,while at the same time providing for arefill interval that the infrastructure can support, and that the owner can easilyintegrate into his operation.If Volvo were required to implement a higher minimum ratio of 5:1, there would be an even greater compromise to cost, weightand utility. To achieve the 5:1 ratio on the CML-77 vehicleshown on page 10, for example, the 70L tank would have to beinstalled. This would bring an additional weight impact of 148 lbs. The weight of theadditionalDEF alone to bring the ratioup to 5:1 on the VNM chassis on slide 4 would come to 195 lbs, with a tank weight increase of about 130 lbs, totaling about325 lbs. Keep in mind that the additional supported weightmeans a nonlinear increase in the weight of supportingbracketry to keep the system stable. The unit on slide 8 would have to sacrifice fuel volume to accept a 5:1 ratio tank.October 8, 2009Volvo Powertrain North America,a division of Mack Trucks, Inc.Supplement to Request for Reduced Maintenance Interval, US10 SCR2REDACTED VERSIONAttached are several discrete examples showing that there are significant chassis modifications required when packaging DEF t nks in therange of 2.3:1 to 2.5:1.These analyses were performed assuming vehicles operating on the upper end of our estimated DEFconsumption rate.Centrally fueled vehicles, usually local ‘vocational’ type applications, can easily maintain a supply of DEF in close proximity to their normal fuelsupply. Volvo Powertrain proposes that itshould be acceptable for the purchaser of a vehicle within this market to spec a vehicle with aslittle as 1:1 ratio to reduce the weight impacts of larger tanks, thereby allowing him to maximize the return on his investment.Certain markets require that a minimum ofvehicle status information is made availableto vehicle operators (for example, fuelgages aresometimes deleted.). For SCR applications, this translatesto a request not to include a DEF gage on the dashboard. Recognizing thatthe absence of the gage presents uncertainty concerning the status of the DEF tank, Volvo Powertrain proposes that a 3:1 minimumDEF/fuel refill ratio is the minimum necessary.Very truly yours,Steve BerryDirector, Government RelationsVolvo PowertrainSeptember 21, 2009Volvo Powertrain North America,a division of Mack Trucks, Inc.Supplement to Request for Reduced Maintenance Interval, US10 SCR3REDACTED VERSIONVNM-5T15_07 (US07)152” Wheelbase100gRound100gRoundVert DPF4 Batt BoxVNM42T200US07 Reference VehicleFuel capacity: 200 gal (100gal + 100gal)Volvo Powertrain North America,a division of Mack Trucks, Inc.Supplement to Request for Reduced Maintenance Interval, US10 SCR4REDACTED VERSIONVNM-39 (US10)154”WheelbaseVNM42T20075gallon(round)HorizontalSCRDPF -RUC125gallon(round)70LUrea3 Batt.BoxUS10 VersionFuel capacity: 200 galRepackage as 125gal + 75galSCR system(+219 to 255 lb)DEF tank & fluid: 18.5 gal(+273 lb)DEF / fuel refill ratio: 2.31Eliminates option for 4 batteriesRequires 2” wheelbase increase (+ 6 lb)Volvo Powertrain North America,a division of Mack Trucks, Inc.Supplement to Request for Reduced Maintenance Interval, US10 SCR5REDACTED VERSION66GRoundVert DPFGU7 8x4REFERENCECML-38GSO48060 (US07)230”WheelbaseRAP 7590US07 Reference VehicleFuel capacity: 66 galVolvo Powertrain North America,a division of Mack Trucks, Inc.Supplement to Request for Reduced Maintenance Interval, US10 SCR6REDACTED VERSION66GD SHAPE27L DEFTANKDPFHOR SCRUS10 VersionGU7 8x4CML-38GSO48060 (US10)230”WheelbaseRAP 7590IN FRAME AIR TANKSFuel capacity: 66 galForces “D” shape fuel tank (adds 13lb, $SCR system(+219 lb)DEF tank & fluid: 7.13 gal(+105 lb)DEF / fuel refill ratio: 2.31Requires In-frame air tanks (adds $Volvo Powertrain North America,a division of Mack Trucks, Inc.Supplement to Request for Reduced Maintenance Interval, US10 SCR7REDACTED VERSIONGSO47911 (US07)168” WheelbaseCXU 6x493gRound93gRoundVert DPF4 Batt BoxUS07 Reference VehicleFuel capacity: 186 galVolvo Powertrain North America,a division of Mack Trucks, Inc.Supplement to Request for Reduced Maintenance Interval, US10 SCR8REDACTED VERSIONCMM-4 (US10)185” WheelbaseCXU 6x493gRound93gRound4 Batt BoxDPF70L Urea tankSCRFuel capacity: 186 galSCR system(+219 lb)DEF tank & fluid: 18.5 gal(+273 lb)DEF / fuel refill ratio: 2.5Fuel volume to be sacrificed to accept a larger DEF tankUS10 VersionVolvo Powertrain North America,a division of Mack Trucks, Inc.Supplement to Request for Reduced Maintenance Interval, US10 SCR9REDACTED VERSION(US07)238” WheelbaseCML 64RUS07 Reference Vehicle3 BatteryBox93 gallon(Round)Fuel capacity: 93 galVolvo Powertrain North America,a division of Mack Trucks, Inc.Supplement to Request for Reduced Maintenance Interval, US10 SCR10REDACTED VERSIONCML-77 (US10)238” WheelbaseCML 64R3 BatteryBox (SpaceSaver)93 gallon (DShape)33L Urea TankHorizontalSCRIn-Frame AirTanksFuel capacity: 93 galRequires “D-shape” fuel tank (adds $ 18 lb)SCR system(+219 lb)DEF tank & fluid: 8.7 gal(+125 lb)DEF / fuel refill ratio: 2.3Requires In-frame air tanks (adds $Requires “space saver” configuration battery box (adds $ )US10 VersionVolvo Powertrain North America,a division of Mack Trucks, Inc.Supplement to Request for Reduced Maintenance Interval, US10 SCR11REDACTED VERSIONCc: (by e-mail)Khesha T. ReedManager, Engine Programs GroupU.S. Environmental Protection AgencyCISD DivisionOffice of Transportation and Air Quality1310 L Street NWWashington, DC 20005Jason GumbsU.S. Environmental Protection AgencyCISD DivisionOffice of Transportation and Air Quality1310 L Street NWWashington, DC 20005David DickinsonAttorney AdvisorUSEPA HeadquartersAriel Rios Building1200 Pennsylvania Avenue, N. W.Mail Code:6405JWashington, DC 20460