Im looking to change my stock 255/70/16 General's to some BFG A/T 265/75/16, I know they wont rub, and the speedo will be of a lil, but what about performance wise? Any difference? I tow a lot and dont want to loose power at all. Thanks.

 

The tire is 5% larger in circumfrence which is about the same as going from a 3.55 gear to 3.73 gear. Plus, the BFG AT is a heavier tire which means more inertia and more effective horsepower. Personally, I would notice the difference, but I cannot say if you will. But, you have the V6/auto so maybe you demand less from your truck than I do.

 

I went from 260/70-16 Generals to 265-70-16 Michelin LTXs and noticed a slight-moderate difference in performance. The difference in sizes maybe only 1/2 inch, but was noticeable, especially off the line and up inclines.

Your 255/70-16 (30.1 inches) vs. 265/75-16 (31.6 inches) will probably be even more noticeable.

After a few weeks, you will get used to it, I don't even notice anymore. The ride and handling of the Michelins make up for it!

See the tire converter page below ...

http://www.s-series.org/htm/calc/tiresizeconv.htm

 

I noticed a loss in highway accelleration when I went from 255/70/16 Generals to 265/70/16 Michelins. The tire calculator I used said there was only a 2% difference in circumferance, but my odometer showed 5% difference. I think it would be very noticeable between 255/70 and 265/75.

If you have 3.55 gears and changed to a 5% bigger tire, it would feel like your gear changed to a 3.38, not a 3.73.

 

Hey guys,

I went from 255's to 265's and noticed a big difference in performance. I didn't notice the change until I hooked up to a trailer, or put some weight in the bed.

with the 6cyl. I would consider going to a 245. You don't have to get the 10ply tires (heavy). You can find many 245's in a 6ply (C rating).

I have the 4.6 and thought it would be ok. It is with no load, and for some it might be fine all the time. I tow fairly often myself and am going to a 245 this spring. Good luck, Rich

 

I went from the stock 255/70/16 Wrangler to 265/70/16 Michelins.

When I pulled out of the parking lot with my new tires on I looked in the back to see if someone had dumped a load of bricks in the bed. The bed was empty so I immediately pulled over and ran to the back to see what in the hell I was towing. There was nothing on the hitch so, I was sure that dose Sums of Beaches had stolen my 5.4L and put a Chevy or Dodge V8 under my hood!
But, none of the things were true.
I had just got a tire that was a little bigger, that's all.

(The Michelins LTX M/S are great on the wet surface and I'm used to them now. I have completely forgotten how fast my truck used to be)

 

I went from the 275/60-17's to 265/70-17's because the Ford Dealer said I wouldn't notice any difference (and Bridgestone doesn't make the Revo in 275/60-17). They were wrong! The new tires are much taller than the Goodyear Eagle GT II's that were on it. I've noticed a significant decrease in gas mileage, and a little less pickup than I had before! I was really hoping the taller tires (e.g. higher rear ratio) might equate to better gas mileage on the highway, but it's dropped 2 mpg consistantly since the swap. I love the Revos traction, I just hope they start making them in 275/60-17 by time I need to replace them again!

 

I will also confirm a performance drop. I went from 2557016 to 2657516 on my 98 3.55 5.4. I did replace the speedo and install a Gibson SideSwept. The exhaust upgrade did help, but there is still a noticable difference on the highway, especially when towing or with allot of weight in the bed. I now have about 55K on the "new" tires and have had no mechanical problems. I am somewhat considering replacing the 3.55 with a 4.10... I think gas mileage will increase.

 

Like PaulT, I also noticed a mileage drop with the wider & taller tires (even after accounting for the speedometer change). I guess the Michelins are stickier and have more rolling resistance and aerodynamic drag than the stock tires.

Overall, my new tires are so much better than the stockers, I am glad I upgraded. But if I were to do it over again, I would go with the 255/70/16 over the 265/70/16 that I bought.

 

Ditto on mine too. Went from 235/70/16 to 265/75/16 and noticed it right out of the parking lot.....

I did adjust the speedo, and that seemed to make it better. At least it shifts much better at any rate.

I do tow a #4500 travel trailer, but I find it still more then capable. I just lock out OD and it runs great. But I do have the 5.4 too.......... You will probably notice more of a "bog" with only the V6.

I did this almost three years ago and have not regretted it! My MPG has not changed that I can tell. I still only get 15 mpg on the highway like it did with the smaller tires.

Running in third at 60 mph, my rpms are around 2300-2400 and I can still make most grades without downshifting.

Good luck!

 

Are you guys sure you're losing MPGs? You went to a larger tire which covers more distance per revolution. This means that for each revolution you are actually travelling a slightly farther distance. This will add up over a tank of gas. So my question is this, "Do you think you're getting less MPGs because you're putting less miles on the odometer?". You may just look that way.

 

I ought to shoot every damn one of you!
I've been reading and studying here for five years.
Where in the hell was this thread before I bought MY tires?

 

suds - can't speak for the others re: mpg loss, but I was accounting for the speedo change, and adding 5% to what my odo showed. I was a little surprised, because I was hoping for an mpg improvement with the taller tires. My mileage varies a lot between tanks anyways, so its hard to be certain how much actual mpg I lost with the tire change.

My theory is the stock tires have unusually low rolling resistance. Also, my actual highway speed may have increased slightly due the speedo reading slower. So if I am pushing the truck a little faster, I would expect worse mpg, even if my rpm is the same as it was with the smaller tires.

Raoul - I felt the same way! I knew my stock tires sucked, and it just seemed a no-brainer to go up one size (more grip, more load carrying, better mileage, etc...) Also, the Michelin page said the 265/70 was only 2% taller than the 255/70, so I thought I would not even notice the performance loss. Then I found the actual difference was 5% taller than my worn stockers, and that 5% taller made a much bigger difference than I would have guessed. Oh well - live and learn.

 

Ok dirt bike dave, thanks for that explanation.

(I'm only going to shoot you in the leg)

 

Raoul, you're funny!

Although I changed my tires before I even filled the tank on this truck, fuel mileage is much less than I expected. I had a 99 Supercab with just about the same options and drivetrain as my 03 Screw so I figured the mpg would be similar, a little less for the extra weight. I usually got 13-15mpg in the old truck. I now get 10-12mpg now matter if towing, city, highway whatever. I went from the OEM 265/70R17 to 285/70R17, but also a P-rated tire to an LT. I attribute my performance (noticable) and mpg losses to the sieze and extra weight of the larger tires.