2015 4x2/4" Rough Countrty Lift & Level/Re Gearing Question

looking for some advice on re gearing my 2015. I just recently got a 4" RC Lift w/ leveling done and went with Toyo ATs 285/70/17 in 35s. Love the ride and look, but have already notice some power loss and decrease in gas mileage. I knew this would happen in advance but wasn't sure how much to expect. Everything else is stock with the exception in an AFE Cold air Intake and SCT X4 programmer. I don't do much hauling with it other than a small trailer for ATVs, ect. Any advice or recommendations would be much appreciated.

Aren’t 285/70/17s 32.5” tall tires?

Toyo AT 285/70R17 = 32.8" tall where I found them.

OP, you shouldn't be seeing much difference in mpg or power loss. Those are not a heck of a lot different than stock tires.

Yea 285/70/17 are not quite as tall as the stock 275/60/20.

OP, you need edit the confusion from your post. You specify two very different tire sizes “285/70/17” and “35s”. And what is your current gearing, 3:21?

Assuming you have 35’s and 3:21’s, I can speak from experience. I upgraded to Mopar 3:92 and an LSD from 3:21s when I put 35s on. I only have a leveling lift, but that shouldn’t matter too much.

If I had to do it all over again, I would have left the gears as is, but definitely did the LSD. The 3:92s did give it the feeling of a bit more power low and midrange, nothing eye opening though. But gas mileage has been almost unaffected when averaging around town and highway together.

Like you I only tow on occasion and fairly light/moderate loads. I can’t say for sure if the 3:92s made a huge difference or not as I never towed anything with the original gear setup and 35s. But if I had to guess I think the truck would have towed fine with the original 3:21s.

I’m not super knowledgeable about drive train setup, so it’s very possible I chose the wrong gear setup or maybe I need a custom tune to maximize mileage and power. Just my personal experience