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Old 01-30-2012, 01:53 PM   #1 (permalink)
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Join Date: Jun 2009
Location: Bay Area, California
Posts: 1,485

Mean Green Toaster Machine - '06 Scion xB
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The dirty cost of one man's hypermiling?

My car failed CA emissions testing recently, and I'm confident my hypermiling had a direct relationship to the problem. When I took it in for the test, I hadn't driven the car in a month, except for a brief drive up the freeway to warm the engine up before the test.

The failure was because some of the drive cycle monitor readiness flags hadn't been set since I cleared the check engine light/malfunction indicator light in October. Since then, I'd driven 800 miles, but the catalytic converter driving cycle is 15 minutes at speeds between 60-100 kph, and I hadn't done that in 4 months.

The next day, I warmed the car up, driving it enough to add 100 miles since the test failure. The car passed smog testing. Examination of the retest shows cleaner emissions after driving the car a distance at speed. Low speed HC results had been 62, only 2 below the maximum allowable level, but dropped to 39 on the retest. Inactivity or the normal way I drive may be raising my emissions, as my HC levels are 3-15X more than average, CO levels are 1-6X the average, and NO levels are 4-7X more than average.

I drove the car 900 miles RT to/from SoCal last week, and the cat stayed lit, between 1101-1185 degrees F. When I do my normal low speed P&G, cat temps are 285-550 degrees F, too low to light the cat.

I know today's cars burn much cleaner than older cars, but I lived through pre-Clean Air Act smog conditions, and I don't like the idea of my car dumping out 3-15X the average air pollution when it's driven normally. I can only guess how bad it is with an unlit cat.

So, P&Gers like me are gross polluters. Lean burn Hondas (including some Insight Is are polluters. The pre-OBDII cars are polluters.

I'm disillusioned by the growing realization that pollution is the hypermiling community's dirt we're sweeping under the carpet.


Boycotting Exxon since 1989, BP since 2010
Have you ever noticed that anybody driving slower than you is an idiot, and anyone going faster than you is a maniac? George Carlin
Mean Green Toaster Machine
49.5 mpg avg over 53,000 miles. 176% of '08 EPA
Best flat drive 94.5 mpg for 10.1 mi
Longest tank 1033 km (642 mi) on 10.56 gal = 60.8 mpg
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