CDC5.0

First off I am not complaining about my gas mileage. Its a truck, its not aerodynamic, its cold out, it has winter tires on it and therefore my gas mileage won't be great.

But I have found that I get better mileage out of the bottom half of my tank. For instance if I fill my tank right up and drive till its around half full (400ish km), mostly highway at 90 km/h, then if I go fill it up again I hand calculate my mileage being around 12.5 L/100km. If I drive the same way but until the tank has about 1/8th left I calculate my mileage as around 11.9 L/100km. I've tried this a couple times this winter and the results are fairly consistent.

I get that the truck gets lighter with less fuel in it however with 1 liter of gas weighing 0.76kg a full 98 liter tank weighs about 75kg which is about 165 lbs. I can't imagine that would make that much difference in my gas mileage. After all 165lbs is like having your gf and a case or two of beer in the truck with you.

Anybody else notice something similar to this? I thought it was kind of interesting.

TheWhiteBeast

When my girlfriend gets in im over payload...

ji603

I see the same thing. Usually get 240 miles on the first half of the tank, then about 260 on the bottom half. Either the fuel gauge doesnt show exactly 1/2 full, or the truck really is that much lighter half empty. I know gas weighs in about 7lbs a gallon, so that's not much... Who knows.

You guys that are hauling around the 165lb+ girlfriends, perhaps it's not the weight, but the drag? Are you towing them in low pro trailers and remembering to add the weight of their feed?

Ford850

First of all, the fuel gauge means little as far as half tank accuracy. But I understand what you are saying. It's interesting though since I have read some pretty extensive studies proving the opposite. They show you get better MPGs by topping off the tank before letting it get down to 1/4 or so. Something to do with fuel pump pressure maybe?

acadianbob

If you have the big 36 gallon tank, and gas at 6 pounds per u.s. gallon, you are talking about a weight difference of 108 pounds (18X6). Are you telling me that you can detect a difference in gas mileage because your truck is 108 pounds lighter? It's kinda hard to believe. Does your mileage go down if the dog gets in the truck? (That is a joke!) Seriously, I really think it would be difficult to detect any difference.

130428

he's saying he's seeing a difference, not that it necessarily comes from the weight difference...
having said that...
i got 14.x L /100km with a full tank on my way down to Calgary, and 12.x starting with just under half and filling up when the fuel light came on on the way back...
i think that's a case for CSI or 24H...

CDC5.0

Now that's funny!

But in all seriousness I don't know why it does this but like I said it has done it pretty consistently all winter.

Wanted33

Oh yeah, I'm tellin' your girlfriend.... then

red1994ford

Only time I really notice a big MPG drop is when I hammer down on the pedal or I really have a bunch of stuff in the bed.

In all honesty, I doubt I would see a significant increase If I removed my toolbox which probably weighs 175-200lbs including all the junk in it.

jmoore9

I found something interesting as well, there isn't any MPG. My 86 Mustang GT got better gas mileage! My gas tank -