What tire pressure for 33" Nitto Grapplers

I'm running 33" Nitto Grapplers on my 2008 Tundra. At what air pressure should I normally keep my tires. They seem to look low to me here lately. The guy at discount tire looked in my door jam and said I should keep them at the factory air pressure. I feel that's not correct since i'm not running factory tires. Can anyone help on this? Thanks in advance!

 

What load range?

If D, 30-33 per the math. A lot of people dont feel "safe" that low.

Otherwise do the chalk line test and see where your at and adjust from there.

 

Yeah thats what the guy tried to tell me I should go with...30 for the front and 33 for the rear.

 

My door recommends 30psi for the front and 33psi for the rear

 

For example

Specs on my tires,
My 285/70/17 LR LR D Yokos

3195lbs @ 65psi = 12780lbs at 65psi

Truck weighs in maybe 5500lbs max

5500lbs/12780lbs = .4304

65psi x .43 = 28psi

This gives you a rough estimate where to start. Then minor adjustments made from there.

I usually ran 30-32 when the trucks dry.

Higher pressure = higher MPGs BUT will wear the inside tread quicker due to the lessened contact patch/ballooning.

As previously mentioned, you'll get a lot of different opinions on the matter.

 

What about e rated tires with a max of 80 psi? Having issues with the trac. It gets better if I drop them down below 30 but it feels like driving a sponge. Had discount swap them out yesterday. I haven't tried airing down below 35 yet.

 

What has not been mentioned.....what are you going to do with these tires?? Daily? Also, once you lose the OEM tires.. Throw out door jam specs. Just sayin.

 

I have toyo AT's (same company)

LT tire- I run them at around 45-50. Perfect for hwy driving IMO. I'll air them down to about 40 and go from there when off-road.

Start at 40 ish and make adjustments as needed until you find the right nbr.

 

Do the chalk test.

Tire folks originally put mine at 35. Looked, felt, drove soft. They can go up to 80 psi as well, so had no clue where to put them. Did the chalk test a few times, and ended up at 42 psi.

 

These will be my daily driver tires and occasionally trail tires.

 

35 ish