School me on AT and larger tires

Ok, with my previous '91 Tacoma on 33's and 08 Jeep on 37's, I have never regeared. All manual transmissions. I didnt care as it's a Jeep with a minivan engine - not built for speed. But never have I had trouble getting out of any mud hole or broken any parts wheeling - 3.21 stock gears on the jeep.

So the question with the new '17 AT, what happens with larger tires on the stock gearing? Do the rpm's sky rocket before shifting or the rpm's drop lower when shifting? I'm sticking to 265 Coopers anyway, but just asking if I do decide to go bigger after the warranty expires.

Excuse the lack of gearing knowledge - a manual is what I've always had and never gave a crap about top speed or gas mileage. I get 12.4mpgs on the jeep today.

 

Larger tires = larger distance at X rpm

You lose low end grunt and add rotating weight (which slows down acceleration), but you will be going faster at x engine speed.

 

I'm catching on, I did notice the lack of low end torque and speed being off with the manual. But what happens to the shift points and rpms on AT? Rev higher before shifting?

 

Not really unless you truly mash the throttle. The new 6 speed auto really wants to keep you at 1500 RPM at ALL times.