280-320 Miles per tank?? WTF

zack birge · May 12, 2014

Like the title says. I have an 08 running SCT IDP Xtreme tunes, 6" lift 35" tires, intake, 5" exhaust. I know the lift and tires are hurting the mileage to some degree, but why is it SO bad. My other 08 with the same setup would go at least another 100 miles of so before I was empty. Anyone know any little secrets to improve the mileage any? Might be trading this in soon on a 1/2 ton diesel.

V-Ref · May 12, 2014

Have recalibrated the speedo for those tires?

I did an experiment on this last tank...Alaska temperaures are different, but by driving my truck around using and accelerations where I never allow the EGTs to get over 700 degrees (basically driving like a grandpa) I pulled an honest 16.8 mpg tank with a small lift and 35s with a CCSB/Auto truck with a mix of highway and city driving.

NY_Mott · May 12, 2014

I have 4" with 35" MT's and get between 300-320. Kind of figured this was normal. Interested to see what others have to say.

zack birge · May 12, 2014

Yes the speedometer is corrected for my tire size.

jimdawg185 · May 12, 2014

Thats not all that bad really. I get between 300 and 400 on stock height and tires. I get about 300- 350 on 35x12.50 stock height.

Clifford_6.4 · May 12, 2014

In stock height and can't get 14+

JMart · May 12, 2014

That was about the norm for my 08 leveled on 35's.

zack birge · May 12, 2014

Dang. I need to just put some tape over the mileage and pretend like its not there then lol

Bair · May 12, 2014

800 miles on a tank here. RCLB so it's a 38 gallon tank.

webb06 · May 12, 2014

im running 295/65r20 tires, stock height and i get right at 380-400 every tank, my truck has quite a bit of work done to it motor wise though that isnt helping the mileage

johnp115 · May 12, 2014

I get 350ish on a tank. Stock height 33's, ofcourse I don't run it all the way down but is just something you gotta get used to.

ghohouston · May 12, 2014

Damn guys, I know it was a dinosaur, but my 2002 7.3 with 238/100's still got 500 per tank with a 35 gallon tank, and I got on it daily, and I have a lead foot. But of course it was stock height on king ranch 18's with small tires with speedo re calculated

webb06 · May 12, 2014

ghohouston said:
Damn guys, I know it was a dinosaur, but my 2002 7.3 with 238/100's still got 500 per tank with a 35 gallon tank, and I got on it daily, and I have a lead foot. But of course it was stock height on king ranch 18's with small tires with speedo re calculated

That big tank helps a little more lol

ghohouston · May 12, 2014

What size tank do 6.4's have?

RedRice589 · May 12, 2014

Well speculation says anywhere from 26 like Black350 up to 38 gallon. Most ccsb have a 30.5 tank. I rarely saw over 300 in my 6.4 with 4.10's and 325/65/18's.

They just eat fuel. All I can say is keep the idle time to a minimum and speed around 65 on average and you'll do better.

ghohouston · May 12, 2014

All that technology, and they still couldn't bring mileage up. I was happy to get a rock steady 14 mpg. I could pull 16 if I drove a long distance on the highway. But that was rare. It was nirmally just my 30 mile one way trips to and from work, most of it spent at 80 mph. What gears do yall have?

johnp115 · May 12, 2014

ghohouston said:
All that technology, and they still couldn't bring mileage up. I was happy to get a rock steady 14 mpg. I could pull 16 if I drove a long distance on the highway. But that was rare. It was nirmally just my 30 mile one way trips to and from work, most of it spent at 80 mph. What gears do yall have?

Newer technology = more fun = heavier foot

That's my best guess lol

RedRice589 · May 12, 2014

I used to and still am lucky to get 11mpg... Not about technology it's driving habits..

KingRanch6.4 · May 13, 2014

Drive to NY regularly from NOVA. 360 miles through hills of PA on I-81.
I've found speed makes all the difference. (Duh, right?)
17.5mpg at 80mph as opposed to tad over 20mpg if obeying speed limits. Average over trip one way.

Hand calc. 3.73 gears. Gearhead Race tune. HighTech quick spools. LivewireTS. 5in turbo back FloPro. No limit intake. Mishimoto CAC/Rad. Stock height Goodyear wranglers

johnp115 · May 13, 2014

KingRanch6.4 said:
Drive to NY regularly from NOVA. 360 miles through hills of PA on I-81.
I've found speed makes all the difference. (Duh, right?)
17.5mpg at 80mph as opposed to tad over 20mpg if obeying speed limits. Average over trip one way.

Hand calc. 3.73 gears. Gearhead Race tune. HighTech quick spools. LivewireTS. 5in turbo back FloPro. No limit intake. Mishimoto CAC/Rad. Stock height Goodyear wranglers

Yeah if you start going over 70, rpms and wind play against your mpg