blueford150

I have a 2009 f-150 with the factory 255 70 17 tires and I want to go a size larger so the tires do not look so small.

Dealer says I can not modify the tires because it can cause transmission problems and the tire warning tire would ALWAYS be on in the dash. Anyone out there put 265 70 17 on there truck to get rid of the sissy factory tires??

Please help, I need winter tires soon

NorCal-09

bs!!

statikuz

Sure, if you threw on 37s you might have transmission problems. But going up around 1/2" in diameter isn't going to cause you any problems. That tire is only marginally larger than the original.

manic5_2001

yeah BS, that dealer is crap and you might want to find another one to do buisness with, they will try to screw you in the future. Unless you go over 38s you will be fine. your speedo will be off but as long as you keep the factory rims no lights will be illuminated on the dash. I think 38s are the maximum for the axle and gearing.

50Ford500

The only way the tire warning indicator would stay on is if
a. you didn't transfer over the TPMS sensors provided you are replacing the wheels as well. and
b. the tires you replaced the originals are run under the min pressure that triggers the warning indicator
So changing just the tires wont really make any issue with the warning indicator

techrep

iTrader: (1)

Thats funny...my service manager told me I could put as big as tires I want on mine as long as they don't rub when turned from lock to lock...thats BS

blueford150

Thanks for the help guys!! I really appreciate it

busbyjay

Your speedometer wont be right but it wont be much since its only have an inch. It will probably be like 1 or 2 miph. If you want to fix that just buy a speedometer calibrator from like hypertech, its about $200 but atleast you will know how fast your going for sure if you care that much.

Platinum_Sean

When replacing a tire/wheel combo, if you want to keep your odometer and speedometer reading accurately, you need to replace the setup with something similar in overall height.

For example: 255 70 17 could be changed to 265 60 18 and the 2 would match in height/circumferance so the speedo would read right.

Going to 265 70 17 (which is wider but has the same profile % and rim) would increase the overall height by 0.55" and make your speedo read 2% slow. Not a big deal.

Your techy dude may be concerned that going to something monsterous (275 65 22 ) would require a visit to the dealer to program your BCM for the new tire size. Then again, he may not know squat.

S

golfguy1ar

Well, sorry to burst everyone's bubble, but the dealer is absolutely correct. I upgraded my 275 65 18's to 295 70 18's and now my traction control warning light flashes and the brakes apply when I turn. This only happens periodically when I turn at slow speeds and mainly when I am going up or down a grade (not level with the surface I am turning from).

After consulting with the dealer, Ford is aware of the problem and are currently working on a upgraded program, so I am told. I was also told that 1 tire size bigger wouldn't have affected anything.