Fuel mileage

[jeshoyt]

I am another newby, but I have a question regarding fuel economy. I bought my F250 from a friend about a month ago. I went on a trip with my ATV in the back and got about 12 mpg. I was wondering if this was normal? I do have a small lift and 35" BFG AT tires on it. I changed out the fuel filter and put a cold air intake on it recently. I am looking for a way to improve the mileage and leaving the truck lifted with tires.

[Banshee34]

Has the truck been recalibrated for the oversized tires? Also did you keep the R's below 2k?

[jeshoyt]

I had a problem with having a heavy foot on my trip so I guess that would affect the mileage. I did go over 2k frequently. I was getting on it uphill to see what it could do on the highway. I have never had it re-calibrated for the bigger tires, not sure if the previous owner did. I was disappointed with the mileage though. Given my set up on the truck, is that a "normal" mpg to expect?

[Banshee34]

Until you know if your odometer is off though, you won't know your true mileage... Knowing your freeway system, you should have a mileage check down there somewhere!

[jeshoyt]

Actually, I didn't think of that. I am going out of town this weekend again and it will be to a place where I know exactly how far I am going (235 miles). So I guess I'll just top it off when I get there and see how many gallons it takes. I was going off the odometer on my last trip. Could have been off.

[Alaska Bush Man]

I have a 99 7.3 that I get in the low 20s during the summer.....only mod I have done is KN forced air induction........and a flow master muffler..........I also use Lucas ejector cleaner often in my fuel.......other than that she is stock.

[Lone Ranger]

Opposite side o da woild... But getting about 18-19 mpg, heavy footed down to about 14-16... 285 BFG Mud Terrains, and a bit heavy of a truck...
Twin long range tanks, 270 litres, air compressor and diff locks front and rear, three batteries, roll bars, alloy deck with 125 watt solar, 80 litre fridge, 15,000 Warn Winch, Snorkle, Bull Bar, Huge Driving lights, big tow hitch assembly and ... and more, like Air Bag over springs suspension, UHF, Stereo, Stacker, Blah Blah Blah, you know the drill, point is pretty heavy...

Heavy footed drops fuel economy, light footed on the roads, pretty good 18-19 mpg..

Cheers, LR in Oz....

[LTJDS]

My list of mods is in my sig.
I do have a 2x4 SRW F350 W/ 20X10'S AND 325/50/20 Cooper ZEON XST's
In Chip setting 4 at 70mph at 2000RPM (40 mpg)
At first I did not believe BUT the new tire Dia. for the non OEM size tires is within 10% of what the OEM tire and wheel Dia is. AND the OEM computer
(Lariat edition) Is saying 40 MPG and the Distance able to be traveled has increased..... NO JOKE !!!!
If you have any ??? please ask
The 4x4 versions do have much more parasitic drag even though their front axle is disengaged in 2x4. I use to own a 99 F250 4x4 on 315/75/16 BFG's,
It had a 5.4L Gas Engine. It was a GAS HOG
When I switched to this PSD 7.3L 2x4 I began saving about $400-$500 a month. That was in two parts due to A. The lower avg cost / gallon of Diesel
compared to premium unleaded and B. The savings in not needing as much Diesel in order to travel my average weekly total comute. A lb. of Diesel does yield more potential BTU"s than a lb. of Unleaded Fuel

[mschn99]

i hate to be the bearer of bad news........

Your overhead computer is VERY inaccurate when you start chipping these truck, it wont display anything even close to what the real distance is.....

And a tire 10% bigger than stock will probably throw it off 6-8 MPH......which is a big differenc it MPH calculations......

Sorry buddy, no way in the world your really getting 40, thats just not possible.....

[LPstroker]

My truck is bone stock, and when i keep my foot out of it I easily get 19. When I get on it it's more like 16. I havn't taken any long trip with it yet to findout what my highway is. I also run Red line Fuel Catalyst. with have made a difference.