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Old 07-15-2009, 09:23 PM   #18 (permalink)
gone-ot
...beats walking...
 
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Quote:
Originally Posted by The Atomic Ass View Post
It was also my assumption that these gauges had to be calibrated to the specific vehicle.
...yes...and, no.

According to the AutoMeter "Installation Instructions" (p/n 2650-1424-00): "...In some cases (primarily with MAP brand vehicles) you may need to fine tune the math formula used by the ecometer to calculate your vehicle's MPG."

...where: "...some engine/vehicle types (most Chrysler vehicles, diesel engines, etc.) you will be required to input a value for the engine size of the vehicle. These vehicles utilize a MAP (manifold air pressure) sensor and the ecometer needs a little more information in order to calculate fuel economy accurately." To my knowledge, the Pontiac Vibe (nee' Toyota Matrix) isn't a MAP vehicle.

However, after a second tank-fillup comparison, a common "tweeking" ratio of between 0.889-0.886 seems to exist. So, I'll crank in a "tweek" number 89 (factory setting is 100, adjustment range is 60-to-140) and see what happens. I'll also check the DSP (displacement in Liters) value which *should* have automatically been set to 1.8, if not, then I'll manually set it too.

As for the other displays, the RPM and MPH displays seem to constantly "cycle" (above, correct, below) by 0.6K rpm/mph, over and over. Maybe it's useful to others, but my wife will never understand it!

However, the MPG-instantaneous display is totally worthless! Random swings between 12mpg to 114mpg while driving with cruise control on don't really *tell* you much, and it NEVER seems to settle down or settle around a common value.

One VERY interesting bit of information is how the MPG-average value clicks down in value -- ie: XX.9...XX.8...XX.7...XX.6, etc. -- as you sit at a stoplight; it really makes you painfully aware that you're "eating" gasoline without gaining milage! And, the numbers click down pretty quickly!

Lastly, the 15 colored LEDS around the circumference of the gauge face act just like a "colorful" vacuum gauge, but a vacuum gauge is much cheaper than the ecometer, ie: red(left) = BAD, orange(central) = poor, green(right) = good.

P.S. -- list price $69.99, got mine for $60.66+S/H.

Last edited by gone-ot; 07-15-2009 at 11:14 PM.. Reason: added cost
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