I trust the computer. Ive found it to be within a couple of tenths or so different from calculating manually. I consider that within a margin of error.
Overall my total average for both city and highway is now 29mpg. I am getting 33 plus easily on the highway and hit just over 36 on one recent drive. Considering that most of my trips are under 10 miles I think this is excellent.
It was commented on way back when that the EPA estimates were conservative for this engine.
Which is why the most accurate calculation is total pumped over as many fill-ups as possible if you don't trust the computer, never just one.
But what's the cumulative margin of error vs. that of the computer? It would be interesting to see a lab comparison, but I feel that either way the error is lost in the rounding.
But those of you who DO record your mileage, please, step right up, and report back with your results... later.
Excellent question. Can't do it in a lab, tho; this is necessarily a real world experiment. We talk about mileage in terms of full miles/gallon-- room for a lot of rounding there.
The margin of error of a gas pump is .05 gal/fill-up, max, and should tend to cancel out over time, assuming the pumps are ACCURATE, which we cannot assume. The margin of error in the computer depends on the precision of the fuel metering, and the quantity reported for mileage calculations may be less precise than the actual metering. Does anyone know the value of that precision?
In any case, and every case, the greater the sample, the lower the rounding error. That's a given.
You can test this anecdotally, if you care enough. Reset the computer and unlink your it from trip A. Just record your fill-ups over an EXTENDED period of time/miles. Months/thousands. If enough people do it accurately and long enough, we might be able to come to a tentative conclusion about how they compare. But we still won't know which is more accurate!
I'd volunteer, but I don't care that much.
But those of you who DO record your mileage, please, step right up, and report back with your results... later.
Same... pump? That's anal alright.
I was getting like 22 in the winter but in the summer I'm getting 28. I'm also making a point to only use brake when necessary and looking far ahead of me to judge when I need to brake or accelerate.
Same... pump? That's anal alright.