I'm going to replace my tires soon and would like some help please.
I have an 04 F150 XLT 4x4 with the 4.6 V8 with 3.55 gear ratio.

The stock tire is 255/70-17 and there is no tire I've found other than the Generals which I'm not considering.

The closest tire size with a good selection of tires to choose from is a 265/70/17. I know this is not much larger, but I want to make sure that by changing size that I'm not going to throw everything out of whack. Buying a programmer is not an option at this time, so the truck's computer will still think it has the stock tires. I currently get great gas mileage, and I'm satisfied with the 4.6, but I don't want to lose any power either.

I'm gunshy about changing tire size, because I changed tire size on a Tahoe once (only went one size up) and it caused my gas mileage to drop drastically. Especially when I hooked a trailer to it. It was like it confused the computer and caused it to drink gas terribly. I know that trailering affects gas mileage, but something was wrong there....I changed the tires back to stock size and had no ill affects from thereon.

I just want some reassurance before I change anything! Please help!
Thanks

PS..If I get the reassurance I need, I've decided to get Nitto Terragrapplers in 265/70-17 I'm thinking those tires will be aggressive enough to take me where I want to go offroad, but not sacrifice a smooth ride on pavement.

 

Go here
and you can see exactly what the difference will be. As far as your old vehicle, probably what changed was the speedometer readings, not your actual milage.

 

It’s true that you might not want to vary the tire size much, as both the odometer and speedometer go off by the same percentage that the diameter change.


There is another tire made in that size, the Bridgestone Dueler A/T

Or you could swap to the 255/65/17, stock on many of these trucks, buy take offs, or buy any of the dozen or so brands available. These would gear your truck down slightly, about 3 percent.
You could also swap for the Lariat wheels/tires 265/60/18 like I did. They are slightly smaller in diameter than your stock wheel/tire combo so at worst it would give you a fraction more power. The rims are heavier, but not bad.
Chris

 

Thanks to both of you for the information!

Robert

 

Also might want to check with your local dealer - they might be able to reset the tire size in the PCM to match your new tires. Most of the new vehicles either have a list of tire sizes in the computer (PCM) or have the ability to enter the size. Should run about $45.00 to get done (that's what we charge)


Dave

 

I took the Continental Contitracs of my F150 supercrew. They are size p255/65/17. Less than 3,000 miles on them. Like new. You can have them for $100 plus shipping. Send me a message via the private message feature on this board.

 

Don't know anything about this site (tiresavings.com) but thay have a Bridgestone Dueler A/T Revo in 255/70R17 for $136 each. Of course, that doesn't include shipping or getting them installed. I've also read good things about those tires.

 

I was also looking for a set of replacement tires for my STX for future reference awhile back. The only alternative to the General's I have found is the Bridgestone AT Dueler's. I dont know if they discontinued these or what because they used to sell them at the tire rack but they don't list them anymore. I did however do a quick search and found them Here. They recieved excellent appraisals from the others who bought them (From the Tire Rack) from what I remeber correctly.

the link is just so you can see the tires i am talking about...I never bought tires from that place so I wouldn't know there rep. The price however seems to be about the same as they were at the rack so I hope this helps.