Need help : Gas Mileage
This is for my brother's truck and not myself. We both recently picked up 2001 model year fords. Mine is a 2001 Excursion, 3.73 and V10. His is a 2001 F250, 3.73 and V10. I am averaging right around 11MPG with mixed driving which is fine. My brother checked his today and he is seeing 6.3MPG hand calculated in city driving over the course of 91 miles.
What would be the first things to check? He isn't throwing any codes, it runs without any issues, no rough idle plenty of power etc.
Any help is appreciated.
Thanks!
Are you saying it took over 15gallons to drive 90miles?
Does it have big hillbilly tires? Those cost fuel. Did he idle a lot? Driving around in 4 wheel drive?
The first thing you should check is its highway mpg. Fill it up and go drive 90miles at 2,000rpm (or less) on a highway.
Running 235/85/16 Cooper AT3's
Stock Gearing
Driving in 4wd as its winter and these tires suck in the winter.
Just had coolant flushed and ujoint replaced. Otherwise shop said it checked out fine.
I topped off, reset the fuel trip meter, drove 91 miles, tank was at half way. Went to gas station and filled up... 13.5 gallons later my truck is topped off again.
So 91/13.5=6.7 (6.7 miles per gallon, correct?)
The shop that did the work said that they thought that it could be possible someone put in the wrong GEM module... They were looking for codes and found a rear window wiper error. Which led them to believe that it could have came from an Excursion. Everything electrical seems to work without issue. Found a receipt that said the ford dealership fixed the electrical.
*shrug*
I know V10 gets a bad rep for mileage, but this is insane. The truck seems to run great from what I can tell... I get my ELM327 tomorrow, so maybe that will help pinpoint something. I already went ahead and purchased the Torque App.
Using rough math.... 25 gallon tank, divide that by 4, equals 6.25 gallons per 1/4 mark. 40 miles divided by 6.25 gallons = 6.4miles per gallon. Still seems to be doing the same mileage.
I bought some MAF cleaner and a new air filter. Once it gets above zero I will replace.
Are you dragging a brake, due to hung up caliper?
Possible your cat is plugged?
Do you know the history of this truck? How's the compression?
I assume you're running the regular 10% crap-anol blended fuel. Do you have access to 100% petro?
Where do you live? What elevation?
Checking the easy stuff is definitely a good place to start (MAF, as mentioned above). But this is so far out of the ordinary that I think something else is going on here.
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haven't checked compression.
yes running the winter fuel at the pump.
I live in Alaska with elevation around 300ft. Hoping torque app helps me a little.
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Depending on how bad your "city" is: that may be just about correct and fair. Coupled with lots of idling to get warm....
Go drive 90miles in 2wd on the highway at 2,000rpm and report back.
Anyhow, here is the latest mileage in 2wd... I will do the 90 mile test ride on the highway as suggested. I used to own a 1994 Ford F150 manual 302 4x4, with it locked in 4x4 and idling a lot I still got 10/mpg easy. I am doing the same type of driving then, as I am doing now in the newer V10.
The reason I specified 90 miles was just because you said that you did 90 miles city driving.
I think you'll get a more accurate measurement the farther you drive for your test. But I know you probably don't want to burn through 25 gallons just to check gas mileage.
I have a question though: are you driving through fresh laid snow? Are you literally making the first tracks in deep snow? Obviously that will hurt your gas mileage too. Just like driving down a sandy beach.… I suppose you've already thought of that since you live in Alaska.
Just to cover the basics: are you filling up the gas tank until the pump shuts itself off? AND the needle is all the way at the top? And you do it at the beginning, and then you do it at the end of your test…?
I don't mean to insult you at all, it's just that 7mpg is crazy low. Semi trucks get better fuel economy I think.
Still waiting on my ELM327 device. So highway in the winter isn't horrid. It's more than likely just that mixed winter fuel causing crappy mileage with this V10. I also rode in my brothers excursion today and his feels much smoother.
I am determined I have a misfire somewhere. At idle it is barely noticeable, but there is a slight vibration as though there is a slight miss every once in a while.
I will just continue driving it and enjoy until I can get my reader to look at cylinder duty cycles and such.









