06 Commander 4.7L V8: Fuel Mileage

[dinkygreg]

Hello guys..
I am new to this site and really like what I have seen so far. Well, I recently picked up a 2006 Jeep Commander 4.7L V8 from a garage. I really like the way it handles/rides, but not pleased with the fuel mileage. I am getting about 14-15 mpg. Is this normal or is there something wrong with my Commander? This is my first jeep, so I don't know much about it. Can anyone suggest me some good tips to get the best fuel mileage?

Thanks.

[Blindman31B]

When I first got mine I was getting about 18-19 highway and 15ish in the city. Im getting 11 mpg now. I know Ive seen a difference in mileage when I went with the FuelSaver program in Superchips especially on the highway.

[strokeZ]

All depends how you drive it. Do you have QTII? Mine varies depends on driving style and use of AC. 14-15 sounds pretty normal, but I have seen as low as 11-12 on mine. I have also seen 17 on a long hwy drive.

[DDDonkey]

I don't drive mine much and when I do, I get 10 city. I can get 14ish on highway, I noticed a big difference when I put the bigger tires on.

[WanderingTs]

I have recently noticed a significant change in my mpg with a change in air pressure. After my lift, at the installers recommendation, I was running 40psi. Per the in dash computer (not accurate because I haven't reset it for the larger tires, but useful for comparison purposes) at 40psi I was getting 10-12mpg. I tried upping that to 45 psi and found that my mpg went up to 12-13mpg. For my last trip I went up to 50 psi and got 15-16 mpg. By this theory, I am hoping that at the max psi for the tires (80psi), the car will actually make gas while driving, but I am thinking 50psi is going to be the sweet spot and don't anticipate any further improvements.

[Sal-XK]

You have to be careful running that amount of tire pressure the 80PSI is the max based on having the max load as well. Just keep an eye on uneven tire wear you run the risk of wearing out the center of the tire faster then the sides with to much air and the opposite with not enough. Doc recommended drawing chalk on the ground and running it over then you can tell how much of your tire has contact with ground.

[jcoulter]

Chalk, hmm? Hadn't heard that one. I'll have to grab the kids sidewalk chalk. :) My buddy once told me about using flour but I never did that cause of the mess it would make.

[strokeZ]

33's w a RR lift? That's pretty good. Did you remove the fender liners?

Just use caution running with that much pressure. I aired up my 265's when I had them to 35 psi and found the XK to be skiddish over bumps - especially bumps on curves. 30 seemed to be the sweet spot. On my 285's I am running 35 and it seems to be civil on the street.

[Sal-XK]

Chalk, hmm? Hadn't heard that one. I'll have to grab the kids sidewalk chalk. :) My buddy once told me about using flour but I never did that cause of the mess it would make.

Ya just draw really thick patch with your kids sidewalk chalk and drive over it. That was Doc's suggestion I never got around to trying it yet. We had this PSI=MPG discussion before. I settled around 40PSI for my needs.