Tire up sizing downside

I currently have 285/55R20 BFG KO2s (32.3" x 11.7" @ 51lbs). Im planning on switching to Cooper AT3 XLTs. Looking at either 275/60 or 275/65. The Coopers are .7" / 1.9" taller, .6" / .7" narrower respectively, and 5lb / 9lb heavier respectively. Preliminary measurements appear to show the 275/65 will fit with little or no modifications (maybe just removing the front guard on the bumper). How will that additional weight affect the truck? 2017 Crewmax 4x4 SR5 with black TSS rims (20 x 9 +50). Stock height, stock black shocks/suspension.

 

Ive run a few tires

oe Michelins(current) at 42 lbs
Bfg 275/65/18 at 51 lbs
toyo 35x12 at 67lbs

massive difference in transmission shifting with the different tires. Dropping down from the bfg to the Michelins has really improved my trans shifting on acceleration and on the highway.

the 35s were awful with stock gears. The taller the height, the lower your rpms get for a given speed. The weight also lowers your mechanical advantage. You can feel it. I do a lot of city driving, so the feel of accelerating is important to me and the P rated tires are much better for that being lighter weight. You could consider a 275/60 in a P rated? Split the height/weight difference


I never felt a handling difference between any, but i have stiffer shocks, braking with taller tires is slightly worse, but our brakes are so large it was more than fine.