Volvo Powertrain North America,a division of Mack Trucks, Inc.Supplement to Request for Reduced Maintenance Interval, US10 SCR1Mr. 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 wouldroughly 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 criticalfactors 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.Attached are several discrete examples showing that there are significant chassis modifications required when packaging DEFtanks in the range of 2.3:1 to 2.5:1.These analyses were performed assuming vehicles operating on the upper end of ourestimated DEF consumption rate.Centrally fueled vehicles, usually local ‘vocational’ type applications,can easily maintain a supply of DEF in close proximity totheir normal fuel supply. Volvo Powertrain proposes that it should be acceptable for the purchaser of a vehicle within thismarket to spec a vehicle with as little as 1:1 ratio to reduce the weight impacts of larger tanks, thereby allowing him tomaximize the return on his investment.September 21, 2009Volvo Powertrain North America,a division of Mack Trucks, Inc.Supplement to Request for Reduced Maintenance Interval, US10 SCR2Certain markets require that a minimum of vehicle status information is made available to vehicle operators (for example, fuelgages are sometimes deleted.). For SCR applications, this translates to a request not to include a DEF gage on thedashboard. Recognizing that the absenceof the gage presents uncertainty concerning the status of the DEF tank, VolvoPowertrain proposes that a 3:1 minimum DEF/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 SCR3VNM-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 SCR4VNM-39 (US10)154”WheelbaseVNM42T20075gallon(round)HorizontalSCRDPF -RUC125gallon(round)70LUrea3 Batt.BoxUS10 VersionFuel capacity: 200 galRepackage as 125gal + 75galDEF tank: 18.5 galDEF / fuel refill ratio: 2.31Eliminates option for 4 batteriesRequires 2” wheelbase increase (adds 6 lb)Volvo Powertrain North America,a division of Mack Trucks, Inc.Supplement to Request for Reduced Maintenance Interval, US10 SCR566GRoundVert 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 SCR666GD SHAPE27L DEFTANKDPFHOR SCRUS10 VersionGU7 8x4CML-38GSO48060 (US10)230”WheelbaseRAP 7590IN FRAME AIR TANKSFuel capacity: 66 galForces “D” shape fuel tank (adds 13lb, $DEF tank: 18.5 galDEF / 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 SCR7GSO47911 (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 SCR8CMM-4 (US10)185” WheelbaseCXU 6x493gRound93gRound4 Batt BoxDPF70L Urea tankSCRFuel capacity: 186 galDEF tank: 18.5 galDEF / fuel refill ratio: 2.5Fuel volume would have 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 SCR9(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 SCR10CML-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)DEF tank: 18.5 galDEF / 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 SCR11Cc: (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