What will be my best route to increase MPG's on my 06 5.4 4x4? Currently I am all stock except for a 2.5 inch leveling kit, K&N drop in filter, and 33 inch Toyo's on stock 20 inch Roush wheels. I've heard that a programmer can increase power and gas mileage. I'm getting about 11 MPG as of now. Most of my driving is highway driving, and I try to keep the RPM's at or below 2k, but sometimes get on the gas if I need to.

If a programmer is the way to go, which programmer can I get for a decent price? And, what kind of MPG gains should I expect? I'm not looking for Prius MPG's, but something better than 11 MPG's. Hoping for at least 15-18. Thanks in advance. Any input would be greatly appreciated.

 

Honestly there is not much. A programmer will help but 1mpg at best.

11 seems like somethings wrong. Maybe your front 4wd hubs are not disengaging. Common vacuum issue.

 

yeah...11mpg is very low, I have 2.5 level with 33's CAI/Spacer/EDGE/Flowmaster and get avg14 around town 17 Highway. What rear end gears do you have and what kind of milage is on your truck ??

 

Have you re-calibrated the speedo so your miles are correct for your calculations? Also what is your maintenance history, more specific driving patterns (highway is pretty broad), etc?

 

My 06 5.4 gets about 16 mpg in mixed driving. Level with 33s. intake, exhaust and programmer. I wouldn't expect much gain from mods either, most of the increases are from driving habits, which it sounds like u are already doing.

 

If I am remembering correctly, when you put larger tires it slows down the rotation of everything in the drive train making the spedo read slower then you are really going, so that would make your odometer read less miles then you actually traveled therefore making your calculated fuel economy read worse then it is. With larger diameter tires you get less revolutions per mile. My stock tires were 235/75/17 which got 673 revolutions per mile and my new tire 285/70/17 gets 617 revolutions per mile. I think that would be enough to drop your calculated fuel economy enough to 11 mpg on the highway. With those tire size changes my spedo reads 5.9% inaccuracy.

 

I have not recalibrated my speedo. Where do I need to go to get it done?

Also, all scheduled maintenance has been done and truck has 56k miles on it if that helps

 

Were you getting 15-18mpg before level and tires?? There is a programmer that you can purchase to correct your mpg.. I forget the name of it.. Some tuners have that capabilities also..

 

I've got an 08 Fx4, with 35's & an Edge Evolution chip & nothing done engine wise. I get about 12-14ish mpg. I don't think the chip does much.

 

is there a way to test to see if they are disengaging????