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Re: Fuel Economy (was Re: Pressure Acummulator Discoveries)

> > The 32 mpg on the road seems high to me.  My trip computer says I get 30-31
> > max at an average open road speed of ~40mph.  Trip averages seem to come in
> > at 26/27 mpg.  This is a 4000CSQ, which isn't as slippery as a 5000, but
> > still...

I don't have the trip computer, but my 4000sq gets 22 very consistently in
city driving, and has hit highs of 27 on extended highway driving (L.A. to
San Jose on one tank of gas!).  When I say very consistently, that means I've
written down the elapsed miles and gallons of gas added to the tank for every
fill-up since I bought the car new in June 1985, so these averages are taken
over lots of samples (approaching 80,000 miles worth).

I'd be very suspicious of a computer claiming that a heavier, equally boxy
Audi 5000 with the same drivetrain gets higher mileage!  Aerodynamics and 
better engine management in some of the newer models (maybe 88 or later, I
don't remember which years things changed) might net some higher numbers...

How do the trip computers measure fuel consumption?


Walter Meares		Intermetrics, Inc.	walter@inmet.inmet.com
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