I put some bfg at's on my '16 f250 6.2 today, 285/70r17 from 245/75r17. Has anyone went to a larger tire and had funny downshifts? I had two hard down shifts on the way home from tire shop that I have never had before. I'm hoping this will go away once the computer relearns. Should I disconnect the battery or anything or just drive it and let it learn? I'm a little disappointed, the tires still look tiny, and checking clearances at liners and radius arms, I could have cleared a lot more tire easily. They sure looked bigger on dads '04. These will do me for a year or so until I can upgrade wheels, tires and suspension.

Before



After
Sorry for the crappy photo, couldn't get the lighting right

 

Ron94150, I have a 2011 F250 Super Duty and I just put new tires and wheels on my truck and experiencing the same thing. It originally came with 18" but it had 20" when I bought it and I replaced them with 20", as well.
I'll be interested to see what others have to offer on this subject.

 

You could always get the speedo recalculated and see if that helps. Your new tire (32.7") is only about an inch taller than the stock (31.5") so I'm not sure how much of a difference that will make. This is my truck with 295/70/18's, and I don't have any hard shift issues:


2015 F250 2.5 Front 3.0 Rear

 

I went with a 285/77/18 and did not experience the hard downshifts. I did experience a groan, vibrating type noise at 50-57mph with the heavier tires. It's like the engine is at too low of an RPM and is struggling. Get up to 60ish and it goes away.

 

I had 1 more funny shift after posting, but it was an up shift into 2nd. I'm happy to say, that after a 100 mile trip and my daily driving this week, everything has been good. I am a little surprised at the amount of performance decrease from such a small increase in tire size. Very noticeable. My speedo is actually spot on with GPS now. Never checked it before the tire swap.

 

You should have gone with a 285/75/17

 

When you change tire size it's always best to change the tire size in the computer. Today's trucks are more sensitive to changes because of traction speed management and engine speed. It messes up the shift points that you are experiencing. It may just go away but for some things the computer will not adjust to because ford doesn't want it to. You can go to the dealer and have them change the settings and be done with it. Also a 1 inch tire has a additional run out of 3.14 inches. As for power loss that comes from new tires. I bought a set of new tires once and got worse fuel millage and it was because the tires need to be broken in. (run through a few heat cycles)

 

I would have if I had been buying them. Dad put these on his 04 a little over a year ago. They have less than 5k on them. He ordered a new '16 and has decided to sell the '04. It has '05+ wheels with the wrong offset, and these tires rubbed the leaf springs pretty hard at full lock. He took my smaller factory tires with 10k on them and they don't run at full lock. All i had to pay was $140 to get them swapped. I can't complain.

 

May be a good excuse for a sct tuner from 5 star. I was going to wait for warranty to be up, but from all the good reviews, I may go ahead with it. I can adjust for tire size with it.

 

Take a look at this thread. https://www.ford-trucks.com/forums/1...ut-dealer.html

You can use forSCAN to adjust tire size and it is free. Just need a $12 bluetooth OBD adapter.