[ewdysar]

I believe that because it is so difficult to get consistant fills in these cars, abd the tanks is only about 10 gallons, a variance of +/- 1/2 gallon can cause your sinlge tank MPG to calculate out with a 10% variance. By doing the math over 10 tanks, the measuring variance drops to 1%. In the AT mileage thread you can see that I overfilled one tank resulting in that tank calculating out to 30mpg and filled regularly the next time with a calculated MPG of 37. If you take 1 gallon from the high mpg tank and add it to the low, they both come out to 33.5 mpg, almost exactly the average that I've gottten over 10 tanks.

In another example: you drive 280 miles on a "full" tank. You go to your favorite station and you pump 8.5 gallons by the second click off. You do the math and end up with 33mpg. You drive another 280 miles, go to the same station and pump, but this day the pump is running a little faster, The pump meter is accurate at any flow rate, but with the faster fill, a couple of air pockets get trapped, and you only get 8 gallons by the second click off. Your mpg calculates to 35, yayyy. You drive another 280 miles but since your tank wasn't quite as full when you started, you drive farther into the tank. Back to the same station and pump, running like it was on the first day, and it takes 9 gallons to fill the tank exactly to where it was the first time. Your mpg has dropped to 31, is something wrong? No, your car has delivered 33 mpg the whole time, the normal fill variances are making your numbers jump all over the place.

The Fit has a very long fill tube which appears to make these variances typical. My 914 has a cap on the top of the tank, you look down the opening and see gas, those fills are more consistant, though a slight slope to the gas station floor can trap air at the other end of the tank and cause a short fill.

The point of this post was to share my opinion that you shouldn't get too excited about high mpg on a single tank, nor should you get bummed if it goes the other way. Keep track over time and you will be able to figure out the mileage that your Fit is actually delivering.

Eric