3.55 Gears and 35" Toyos - Bad Idea?

[1stgear]

I just picked up my 2010 F250 (Switched over from a 2008 Durmax) and LOVE it! I'm thinking about changing from stock tires to a 35" Toyo MT. Is this a bad idea with my 3.55 gear? I ran the same tire on my Duramax and lost mpg and when going up hill the truck would downshift.

Any help would be appreciated!

THANKS!

[1tonpower]

your going to notice it just like you did in the durra slap.

theres a 10inch difference in circumference between a 32 and a 35 inch tire.

thats going to change your 3.55 to more like 3.25s

[michigan37]

What tire and rim combo did you have from the factory? Because the 275/65/20 that come factory are over 34". I didn't notice that big of a difference switching to the 285/65/20 (34.8"). Hope this helps.

[1stgear]

I guess it would have helped to post that tidbit! Yes, I did get the 275/65/20. Thanks for the replies.

[michigan37]

You'll have to put some pics up after you switch the tires. 35's look so much better than the 275. I have to find a good AT 35 for my next tire that can get some serious miles out of.

[6.4turbo]

I went from the continetal 33s to toyo 35 ATs and went from 14.2 to 12.8 on avg. on the lie-o-meter. No problem on the down shifting though, but I have the 3.73s.

[96bronco]

If you have the 275/65/20 the difference will be minimal. Your stock tire is already 34x11x20. I doubt you will notice excessive downshifting. Your mpg may suffer minimally, but not much.

[WVStroker]

I'm interested in this too. I have the factory 275/65/20's and 3.55's. I'd like to at least go 35's, maybe even 37 toyo's. I was afraid the 37's may just be too much for the 3.55's though. Anybody made these changes and did some towing afterwards for comparison??

[1tonpower]

disregard my last...moving from a 34 to a 35 with give you an adjust ratio of 3.45...go for it

[haccpguy]

I lost about 2.5 mpg's when I went to the 35 Toyo MT's. Still plenty of power though.