I have an 06 5.4 screw larait 150.. I get 16 for the most part... I have a k&n intake and thats it... I think it all depends on how you drive. When im mad or pissed off I usualy only get around 12-13

 

My guess is that the folks that are getting better than ~12city/~14.5-15hwy are 2wd trucks.

 

I didn't think about that. They must be.

 

4x4 on 35"s

 

FSU, I would say you should be ecstatic with your fuel mileage. When I was running 34's I was getting about 12 around town and 13-13.5 on highway. Currently I have 33's and still get around 12 in town and 14.5 on hwy with cruise set at 70.

 

It may be worth keepin the programmer then

 

what programer and what settings

 

Gryphon. 87 performance. I've adjusted shift points, shift firmness, lock points, . Haven't touched timing for fuel

 

Did you set the shift points and lock points lower?

 

05 XLT 5.4. 3.73 gears. Gryphon with custom tunes and set on level 3 (93 octane performance tune) gotts mod, magnaflow duals, 33" tires. 13.5-14 city and 20-21 highway. Done a lot of adjusting with my programmer to get it to that though. And as mentioned before, keep it under 2,000rpm and mpg will makes drastic jump.