I have auto with 35's and turning 1200 rpm's at 45mph with OD on. Just wondering if the low rpm's are ok?

 

It will help contribute to carbon deposits which can cause pinging

 

Been running 35's on my JK for a few years. Outside of crabby gas mileage, all is good. The lack of power does get annoying, but I knew that going into it. Nothing a supercharger and/or gears won't fix

 

I'm on stock tires, and I keep O/D off all the time I'm not on the highway. I keep it off even when going 50 mph on non-highway type roads because of all the hills. The Jeep performs better, and the rpm isn't excessive. MPG doesn't seem to take a hit, probably because it's not constantly up and down shifting. The torque converter stays locked, too.
I like to keep the engine around 2,000 rpm, or a little higher. In my opinion, it's good for the engine.

 

^ x2 to this.....