So from a physics point of view, the manufacturer specs are pretty much worthless once you change width, sidewall, dia, tread thickness, sidewall strength, etc.. at least when it's a large change.

I just installed 275/55/20 Falken Wildpeaks, and when I mounted them I just aired them up to 35psi because I wasn't sure how they'd balance and I wanted the good ones up front (no balancer here).

So these things at 35 feel like my old tires at ~28or so. I'm going to double check the pressures, especially since it was 65 degrees in the shop when I mounted them and it's now 15 degrees outside(!).

Having said that, has anyone figured out the sweet spot for wider, heavier, and taller tires on the LR3 / RRS / LR4? I know I'll have to add a ~6psi bias to the rears when I check them this evening which should help a lot as well.

The extra 2" diameter (somehow I'm at 31.9" with zero rubbing? rhino rods get here today though..) made a bigger impact on final drive ratio than I thought, and I definitely feel it with the shift points and power "overhead" loss.

Amazingly when it was warmer on Friday they felt nearly stock, slightly better ride than the stock 19's, but the rig as a whole was just more sluggish. Tires seem great, final drive ratio impact was the thing that stood out.

Anyways hoping 36psi front and maybe 42 rear (in the cold) would be good. Can anyone with larger A/T's chime in?

PS sorry for starting so many random threads lately!

 

toyo at2 265/60/r18's

run 38 front, 42 rear. Good Setup.

 

I run around 42 psi without thinking too much about it. I also can corroborate that you don't need the lift when running around town with tires of that diameter. Try that on a trail though, or in Access height...and you'll rub.

The vehicle definitely feels different with the extra unsprung weight and rolling resistance. I don't know that I'd call it "sluggish" but it's certainly less responsive and you can feel the extra inertia.

The benefits you realize off the road with bigger meatier tires are the same as the benefits of having OE sized road tread for when you're on tarmac.