Quote:
Originally Posted by tom43571
I bought one and it is wildly inaccurate. It is more of a random number generator than an MPG gauge.
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...I just installed an
AutoMeter 9100 ecometer (MPG gauge) in my '09 Vibe and encountered similar results: (a) only the MPG-average display is usable; (b) the three other displays (MPG-instantaneous, MPH and RPM)
never seem to settle-down on a single number, even at constant freeway speed with cruise control engaged...you'd expect the MPH and RPM numbers to be stable under these conditions.
...I can somewhat rationalize the fluctuations in MPG-inst. because every wind-gust, bump in the road and incline/decline are being "adjusted" via fuel-squirt volume and duration by the ECU, so swings coinciding with road conditions makes sense, however, this doesn't seem to hold for the ecometer.
...and, unless I did something wrong (which has a high probability), the first gauge reading was 38.2 mpg vs. actual tank-fillup of 34.4 mph...or 0.89 "tweeking" factor. Am on second tank now to get a "second opinion" before I attempt their "efficiency number = 100" recalibration process.
...stay tuned.