EPA vs Euro IV emmissions standards

[CTX-SLPR]

Dan,

This is big for you but anyone know the big differences on why a Euro IV diesel vehicle wouldn't meet US EPA standards for the same year?

[DanStokes]

Re: EPA vs Euro IV emmissions standards

The last I knew (this knowledge is a bit dated), the Euro standards were based on a series of steady state measurements whereas the US standards are based on a transient test. Short translation - the Europeans run a series of speed/load points, allow the engine to stabilize, take a reading, and go to the next point. The US test "drives" the engine over a continuously varying test schedule so that the engine is exposed to the transient changes in speed and load it would see in actual use.

NOTE: ALL HD tests are performed with the engine only on an engine dyno. This is necessary because the chassis into which the engines could be installed vary so wildly that it's almost impossible to determine a "typical" chassis. In this case, "chassis" includes anything that could influence engine performance, such as transmission type and number of gears, rear axle configuration and ratio, etc, etc. There are single and twin screw HD chassis dynos that are in use every day, but emissions results from them must be considered developmental. The EPA has a new HD chassis dyno installation and there was some discussion of coming up with a chassis dyno certification test but I don't think this has been done and I question the correlation between the two.

Not completely sure why the Europeans stick with a steady state type test other than it can be performed on an Eddy current dyno , which can't motor the engine. I'm guessing the Euro manufacturers have pushed for this. The US-style test requires a motoring dyno (DC or Flux-Vectored AC).

Again, let me stress that all this info is dated and may or may not still hold true. So to answer your question - it's apples and oranges. This is not to say that if you ran a Euro certified engine on a US certified site that it wouldn't pass - just that it hasn't had that expensive US test.

Dan

[CTX-SLPR]

Re: EPA vs Euro IV emmissions standards

Us it possible to get a vehicle certified by yourself or is it something that the OEMs would have to do? The Jaguar XJ6 diesel is one tempting piece of engineering.

[DanStokes]

Re: EPA vs Euro IV emmissions standards

The short answer is yes, you can. Give me a little time to look into it and I'll see if I can find a lab for you in your area. Traditionally it's pretty pricey, though. The lab my brother's girlfriend runs (she's the tech guru) in Philadelphia may be able to do it but I don't recall that they had a chassis dyno when I was last there. Any private lab that will do this has to have a heated FID (HC) and NoX analyzer and the ability to measure particulate matter (PM) gravimetrically. None of this stuff is easy. I know the PA lab has all the stuff - except maybe the dyno. They do a TON of Diesel engine dyno work both for the company that owns the lab and contracted work for others. I'll drop 'em an Email and see what they say. If not, Holly probably knows who can do it. I'll also find out who to contact at the EPA to submit an application.

Dan