Tires: Tire pressure, bf goodrich all terrain, tire placard

Question
I drive A 2007 Tundra double cab 4x4. I was wondering what the proper air pressure is for a BF Goodrich All Terrain tire size LT 285 65R 18? I mostly drive on highway.



       Thanks for your time!

Answer
Kevin,

On every vehicle sold in the US – and I am told this is worldwide, but I have not been able to verify this - there is a sticker – commonly called the tire placard - that lists the original tire size and the proper pressure for that size.  The placard is usually located on a doorpost or in the glove box – but sometimes it is located in the trunk or on the fuel filler door.

BTW, it doesn't matter who makes the tire or what pressure is listed on the tire's sidewall, if the tire size is the same as the placard, then the pressure listed on placard is also appropriate.

One word of caution:  Some trucks use tires with the letters "LT" in front of the tire size - and some trucks use tires with the letter "P" in front of the tire size - and some trucks use tires with the letter "C" after the tire size.  You should not use "P"'s in place of "LT"'s and vice versa.

If you are using a tire size that is different than what is listed on the placard, then the pressure has to be recalculated.  The calculation is not difficult, but it requires tire load tables which are not allowed to be published in the Internet because of copyright laws.

So the first step is to check to see what the vehicle tire placard says.  According to Tire Guides - a book that summarizes vehicle tire placards - a 2007 Toyota Tundra 4X4 Double Cab originally came with a number of different tire sizes:  P245/75R16's inflated to 29 psi front and rear, P265/70R16's inflated to 29 psi front 32 psi rear, or P265/65R17's inflated to 29 psi front and rear.

There appears to be a problem with what Tire Guides says, so I think this needs to be verified on your truck.  This is important because what comes next is dependent on this information being correct.

I'm going to pick the worst case:  P265/70R16 with 29/32 psi.  In order to carry the same load, an LT285/65R18 needs to use 35 psi front / 37 psi rear.