05Raptor

I also just remembered that the speedometer might not be calibrated. And since it's lifted would a super chip help? I think it can reprogram like shift timing, gas/air mixture, calibrate speedo, and change the gearing, all of which would help. I can definately drive more conservatively too. Any reviews on super chips would be appreciated.

reknelb

To the guys getting 11-13mph, check to make sure your hubs aren't stuck in the locked position. They are vacume operated and when they fail they Will keep the hubs locked, thus spinning all you drive shafts as if u had it Im 4wd fulltime sucking your mph down.

tomb1269

Nope, mine been replaced...getting 11 to 12 in town (city type), getting 13.5 to 15 highway (70-75) /country road (55 -65). Best ever (only had truck last 10k miles currently 92k on clock) 16 but that was 70-72 very light on throttle. This is all on 10% ethynoal as you cannot buy non-E gas anymore.

reknelb

I just wanted to throw that out there because a good friend of mine drove with them stuck on for years getting 13mph , and my mechanic said in his experience with fords 50 percent are stuck on.

rugerchiro

Have a 2004 Screw Lariat 4x4 with leveling kit and 295/65/18 Duratracs. When I bought it new in 2004 the best stock I was getting was 16-18 highway. Just had reman engine put in after the engine went at 210,000. I have been getting about 11-12 mpg using 87 octane...just put in 93 octane today and now getting 13.9-14.1 mpg. Fuel type could be one factor.

What can I do to get the 14 city and 21 highway??

afg

Im getting about 12 mpg 97% city driving. And my foot is made of lead. All stock only 37k miles.

05Raptor

I know this is kind of an old thread, but I get about 10 with 35s. If the hubs are stuck on, would the front wheels pull as if it were in 4wd? And would the axles be rotating when I'm driving?

Kokeshx4

What would be a good way to check if the hubs are stuck locked in that u could do myself at home??? It dosent feel lik thy are when i make sharp turns. I also use my 4wd on a regular basis lately But who knows right???

dyeguy1212

iTrader: (1)

While in 2wd, the CVs and front diff would be moving, but there's no "pull", as your transfer case isnt engaged.

Search the subject, there's 100 threads.

NDIrish_147

with the truck in park and running in 2wd get under it and see if you can spin the front drive shaft. if you can and both half shafts spin you are good to go. if not you have a leak