Quote:
Originally Posted by Pravus Prime
2. That ones a bit harder to answer. It is the last 2000 data points collected, but we've had a difficult time getting just what those last 2000 are. However, if you reset it with each tank, it'll be a good estimate of your MPGs. You may find, as Tim does, that it reads high, but we've gotten a mix, from 2 MPG high to 3 MPG low, so you'll have to see for yourself. (I've had it both ways incidently, and spot on many times.)
|
I think the NAV may be more accurate than some think. The problem is with "manual calculation".
I've got a ScanGuage II and you are supposed to make an adjustment on it during your fillups to ensure its accuracy. The adjustment consists of using the same pump to fill the tank twice, and then looking at the amount of gas used and checking it with the readout on the gas pump. I've done this several times (like 10 or more). Frankly, using the same pump, on the first automatic shutoff, the results are NOT VERY CONSISTENT! I've even tried a different pump to see if it would be more consistent. I've ended up with adjustment % numbers on the ScanGuage everywhere from 4% to over 10%. 6% seems to be the most common... and strangely, when I use about 6%, the ScanGuage reads pretty much in line with my NAV about +/- 0.5MPG (until I get a few days into a tank and I'm past the 2000 points).