Need your thoughs.... I have a 2010 F-150 5.4L V8 Flex Fuel 4x4 4-door. I recently installed a 6" lift kit and 295/70/18 Nitto Trail Grappers. I have calculating the mileage and I am getting right around 13 miles/gallon. Before I install the lift kit, about 2 months ago the truck started running rough and the check engine light came on. I had the code check out and it was for an oxygen sensor (unsure of which one now). I was recommended some fuel treatment and the code was re-set. The check engine light has not came back on since but I noticed i lost around 50-75 miles per tank. I know with the bigger tires now on the truck that I will lose mileage per gallon, but does 13 per gallon seem about right?

 

With those tires and that big a lift, that sounds about right. Have you corrected the speedo/odometer for the larger tires? You should probably get a programmer and some custom tunes.

 

I have not corrected the speedo/odometer. I have not put 500 mileages on the truck since the lift kit. I have good and bad about programmers. What is your thought? Make and model?

 

18mpg here....2010 F-150 5.4L V8 Flex Fuel 4x4 Scab, no lift, stock 20's

Never had a lifted truck or a larger tire setup but doesn't seem too hateful...

 

SCT X4 from one of the reputable custom tuning houses.

 

If you didn't adjust for your taller tires, your odo/speedo is off and showing less miles than actually traveled.

So, if you are taking the miles off the odo or relying on the computers mpg figures, it's gonna be off.

Get your comp programmed for the new size tires and it'll shift better and your actual mpgs will come back some.. You'll still lose a bit for the larger tires, but that's the price you pay for it!

Good luck!

Mitch

 

Sounds close.

I had an 08 screw 4x4 on 35s. Without my tuner I saw approx 12 mpg. With gotts and exhaust I saw 1 more mpg. When I got a tuner with a tube I picked up 4 more mpg. Get a tuner.

 

Couple of things you should do.
1
Re gear the truck as close as possible then recalibrate the tach/speedo.
2.the o2 sensor could be the air/fuel ratio sensor causing the rough idle.
with having a lift kit your truck does indeed become a giant wind sock. Hope this helps