From: david.kayes@daimler.com

To: Byron Bunker/AA/USEPA/US@EPA Cc: donald.keski

- hynnila@daimler.com, brian.burton@daimler.com, francis.seymour_jr@daimler.com Date: 07/14/2011 07:49 PM Subject: Further issues re. the HDV GHG regs

By ron, A few mo re quick issues that I want to follow up on, after our discussion a few weeks ago: A very important issue for us is changing the date of manufacture definition. I am not sure that we ma de this sufficiently clear during our discussions before. Our VIN, which includes a model year designation, is stamped on frame rails in advance of a vehicle build. W e cannot change that VIN without great difficulty once the vehicle begins its build process. The EPA's proposed build date (and in turn, model year designa tion) would depend on the last date of manufacturing, which can vary significantly ( e.g. , if one single part is out of stock, such that a vehicle goes into "off

- line"). The EPA proposed limiting this just to manufacturing at the main production facility, but that does not solve the problem. Rather, the agenc y would put us in the difficult position of having to restamp frame rails every time a part shortage pushes a vehicle from one year's build period to the next, since those vehicles are still at the mai n production facility. Moreover, the EPA's proposed requirement would potentially lead to different VINs for NHTSA as for the EPA. (Recall that NHTSA does not have such a build completion provision.) To resolve these issues, I recommend that the EPA use a build date specification that is more simple to nail down, like the engine

- in

- chassis date or the date on which rails start down the vehicle manufacturer's assembly line. In June the EPA suggested adding a requirement for use of a wind tunnel that the w ind tunnel meet SAE J1252 specifications. This is problematic for Daimler and perhaps for every vehicle ma nufacturer in the US because of the blockage ratio requirement. Section 5.2 of 1252 limits tunnels to a blockage ratio of 1/20 at 0 degrees yaw and 0.3 at max yaw. Wi th Daimler's contoured wind tunnel, this is not possible, so we would be unable to use otherwise good data from this wind tunnel. Wi th the NRC wind tunnel and a full sized trailer, I am not sure that the ya wed blockage ratio can be met. (Perhaps it can, but I think not, just because so much side area becomes exposed. I bet Arvon or Prashanth know better than me.) In short, I request at least the possibility that Daimler be able to certify our non

- 1252 tunnel so that we can use data from it. Lastly, a new issue that just came to m y attention: some fleets (like Wa ste Management) and natural gas engine manufacturers (like Cummins We stport) suggested in their Januar y comments to the EPA that natural gas vehicles should be eligible for a c redit multiplier like the 6.67x multiplier available for LDVs using natural gas, an option presented but dropped in the NPRM. (75 FR 74198.) I know that HDEs will benefit from the low CO2 emissions of natural gas. But HDVs could definitely benefit from a credit for natural gas use, like LDVs do. I do not know what is the correct multiplier, 6.67 or something else, but advanced technologies may get a 1.5x multiplier. Perhaps natural gas vehicles should too, since NGVs are quite expensive, like hybrids. Or, perhaps the natural gas engines should get credits with a 1.5x multiplier that are fungible like advanced technology credits. Regards, Dave

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