Derf00

that kind of stop and go driving kills mpg. I used to live in southern cali and most of the traffic controls there work the complete opposite of what is common sense and would actually control the flow of traffic. they just create it.

That being said, you cannot go by the readout (that's why no one talks about it).

Top off the fuel tank and reset your trip meter. When you go to fill up next time, take the number of miles recorded and divide it by the number of gallons needed to top your car off again. THAT is the only real way to get an accurate MPG of your car.

I can resent mine all day long and If I drive it like I stole it for a half mile then baby it the next, my MPG readout is crap (low).

JimC

The readout from the computer is no less or more accurate than hand calculation. Both are going to be an approximation. The only way that hand calculation is going to more accurate is if each time you fill up the car you do so to the same exact point without fail, and that the pressure delivered by the gas pump is exactly the same each time.

I find that if I hand calculate and compare it to the computer read out (after clearing the computer read out with each fill up too) - the figures are always within a tenth of each other, and sometimes exactly the same.

In my opinion, I just use the computer because it knows how much gas has been sent through the injectors and for how many miles. The hand calculation has always been almost the same and the difference in how much the fill up is could account for some of that.

cruisin5268d

Get it checked, and track your economy from tank to tank. If you track it over short distances in the city then you will see very low numbers.

Chromeshadow

Jim, yours may read correctly, mine reads 5% low at best, and will show a huge drop in mileage at times that is not mathmatically possible. I drove on the highway for 4 hrs at 70 mph, getting 31 mpg. I hit a couple of curves and the readout went down to 16 mpg. Mine "weighs" the poor mileage numbers higher than the good numbers when it does the average.