EPA Hydrocarbon Test Anomally
EPA Hydrocarbon Test Anomally
(OP)
I just read in a motorcycle publication about EPA hydrocarbon emission results for motorcycle vs truck and they seem counterintuitive to me. Specifically, a BMW motorcycle getting 45mpg emitted hydrocarbons at a level of 1.5/mile and a Ford F-150 getting 15mpg emitted only 0.1/mile. How can this be? Is it somehow do to the BMW having more combustion events per mile,or something like that? Both vehicles were fuel injected, with catalytic converters.





RE: EPA Hydrocarbon Test Anomally
The cat system may be a small part of it, but to achieve modern levels of HC emissions you need to address things like permeability of fuel tanks, and so on.
Cheers
Greg Locock
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RE: EPA Hydrocarbon Test Anomally
The standards for motorcycles are (for now) a lot less stringent than the standards for automobiles. The catalytic converters are designed to meet the standards in each case. There's no point using an expensive, really efficient catalytic converter when a cheaper but less efficient one will achieve compliance.
RE: EPA Hydrocarbon Test Anomally
RE: EPA Hydrocarbon Test Anomally
RE: EPA Hydrocarbon Test Anomally
Cheers
Greg Locock
SIG:Please see FAQ731-376: Eng-Tips.com Forum Policies for tips on how to make the best use of Eng-Tips.
RE: EPA Hydrocarbon Test Anomally
The shed test measures all evaporative emissions, including tires, interior, all fabrics, gas tank, etc. I saw a Subaru that failed a shed test because the owner sent it through a detail shop first, where they sprayed the engine compartment and tires with a preservative. The real stinker was the tire shine compound.
Franz
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