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Old 03-03-2010, 09:02 PM   #197 (permalink)
Christ
Moderate your Moderation.
 
Join Date: Nov 2008
Location: Troy, Pa.
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Pasta - '96 Volkswagen Passat TDi
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Quote:
Originally Posted by hackish View Post
If you are keeping the key on the whole time then you're obviously not losing the connection. This still does not account for the fact that not every auto manufacturer reports the injectorpw correctly. I also know that the estimated fuel economy is approximate because I worked on the math used for several OE's. They gave an acceptable range in their spec and it was 15-20%. We tested it and just scaled the values slightly so if you did the math manually you'd be in the same ballpark. This means if you're trying some special technique and showing a difference it may or may not be real - it may just be tricking the simplistic model. This is why my reliance is more on the old school method of measuring the litres used.
Calibration and averages account for the inaccuracy of the system, like I said earlier.

The gauges are calibrated based on inputs from the vehicle, specifically. After a few tanks are calculated, the output from the gauge can be calibrated to show the same approximate value as the "old math" shows time after time.

Even an abacus is incorrect until you actually do the work to solve the problem.
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