what should the new air pressure be with these LT Tires?

OE tires that are on my truck LT285/55R20
placard is at 49psi for front and rear tires…

If I were to change to different tires and wheels lets say too LT305/70/18

what should the new air pressure be with these LT Tires?Curious if the new LT tires will stay the same?Will the air pressure need to be different on the fronts and rear?

 

Chalk test is best for any new set of tires to find the sweet spot.

For me, front and rear are different for my ride preferences. Unless I'm loaded in the back, I like a bit more up front than rear. When I really load up the bed or am towing I add some extra air in the rear. I like ~48 psi in rear when towing and low 30s when empty. But I'm on stock 18" oems so your sweet spot will be different.

 

I have mine at 40. 305 70 R18 KO2s

 

My LT’s per Nitto when I called them to get their recommendation.

Front: 34
Rear: 32

 

This comes up a lot by the way - the search feature is very helpful especially when you cross into E load rating territory. Whoever sells you the tires would help too.

 

Chalk test.

I have E's at 36 front, 34 rear.