I just got my 285/65/18 Nitto Terra Grapplers mounted and couldnt be happier, but I am unsure at what pressure to run in them. I checked them once I got home and they are all different ranging from 35-45psi. I looked at the sidewall for the "max psi" and it says 80psi. So what should I run them at for basic city/highway driving and for max tread life? I was leaning toward 50-60psi?

 

on a 10 ply tire such as yours you should not go below 50 psi.

 

50 - 55 sounds right.

 

i have 265/75/16's on my stock rims and the place i got them at put 35psi and that that is what they should be like the stock specs, i have them at 40 should i go higher? thanks.

 

Depends upon the max pressure and load range. Without those,no one can give you a correct answer.

To the OP, use 50. That should give you good tread wear and be able to handle anything up to the rating limits of your truck.

 

Thanks guys, sounds like 50-55 will be the best for me. I just couldnt believe that after I spent like 1k at discount tire my tires are all about 10 psi different from each other. The one thats at 35 looks low. I just want them to last me a while and wear evenly.

 

35 on a LR E with a max of 80 is not just low. It is dangerous. Always better to be a bit overinflated (as long as it is not over the max), than underinflated.

 

load range d and max psi is 65. thanks.

 

Those should be run at around 45. Go no lower than 40-42. At 45 you should be good for anything up to the ratings of your truck. May want to go a few psi more if you tow anything real heavy.

 

I put them all at 60 today and it rode a lot rougher and seemed to bounce over small bumps. I just put them at 55 and will drive it later and see. I will probably leave them alone. I never tow or haul anything heavy, so I think 55 is good.

I also had a slight steering wheel vibration at anything over 55mph. I am getting the alignment tomorrow morning and if it still shakes, back to discount tire.....I will also ask them why all my tires where 10psi different from each other and the lowest was at about 33psi....

Link to pics of them installed: https://www.f150online.com/forums/20...new-tires.html