Fuel Economy - Revisited

[rcpd34]

I have a 2000 E450 Class C. Just got back from a trip from MD to ME and back. Towing a Jeep TJ. Got 7.5mpg on the trip up and 11.5mpg on the way back. Both hand calculated. Can't figure out the disparity. Had AC on both ways most of the time; no generator running. Only difference was on the way back I filled up in NJ where you can't pump yourself and the attendant may not have topped off like I do, but that would only account for a a half gallon, maybe. Thoughts?

[burlmart]

TyroneandGladys wrote:
I am confused if you figure your MPG by how many gallons of fuel you bought and how many miles you drove what difference does how full your tank was at a fill up?

Right. 2 diff things. The full remark was bases on goung from full tank down low, and refilling, then hand calculate mpg as tank odo divided by gallons to refill.

as a check - and not all that useful in this case - total trip miles divided by gallons bought. But with a 7.5-11.5 range, I do not thing an avg of 9.5 tells us much

[TyroneandGladys]

I am confused if you figure your MPG by how many gallons of fuel you bought and how many miles you drove what difference does how full your tank was at a fill up?

[burlmart]

rcpd34 wrote:
I have a 2000 E450 Class C. Just got back from a trip from MD to ME and back. Towing a Jeep TJ. Got 7.5mpg on the trip up and 11.5mpg on the way back. Both hand calculated. Can't figure out the disparity. Had AC on both ways most of the time; no generator running. Only difference was on the way back I filled up in NJ where you can't pump yourself and the attendant may not have topped off like I do, but that would only account for a a half gallon, maybe. Thoughts?

Will assume gas needle was on FULL after NJ guy...Is the braking thing on your toad malfunctioning? 7 v 11 is too big a difference.


May wanna' check all receipts, if available, and get an overall mpg.

[tatest]

You can't fill consistently enough to make sense of the calculation for any single fillup. Averaging over 3000 miles, 10,000 miles, filling differences will average out, so you get a better idea of how you are doing.

The fiiler neck on a C will hold at least a gallon. Plus or minus that much can be a big proportion of a partial fill.

A much bigger problem on my Fit, as the tank will hold slightly over nine gallons, the filler neck almost two. Pump can shut off any time the filler neck is filling, some nozzles are more sensitive to vapor pressure than others. I can see 32 or I can see 43 depending on how much I got in the filler neck last time vs this time.

[stickdog]

I don't know but I do think there is a difference in the go power of diesel. I do know there is a difference between #1 and #2. With gas there are different blends which affect MPG's.

[IAMICHABOD]

Aw that's easy, on the way UP you were draggin the Jeep on the way DOWN It was pushing ya :B

Sorry couldn't resist...................