Tire Pressure Question

Just wondering how much air pressure you guys put in your tires? Do you go by what is on the door jamb of the truck, or go by what is on the side wall of the tire? The door jamb on my Taco says 30 psi cold for P245/75R16's. The truck came with Dunlop Grandtrek AT 20's in that size. I have always on all of my vehicles used the max psi on the side wall of the tire minus 10%. I have always had excellent wear on my tires by doing it this way. I checked these Dunlops today and max psi is 51 lbs. So I just rounded the psi to 50 x 10% or 5 psi. So I should air up the tires to 45 psi if I do it like I always have. I checked the tires and all 4 tires had 37 psi in them. I went ahead and aired all 4 tires to 45 psi. My question is this - Why would you put on the door jamb that your tires should be 30 psi cold and then put a tire on the truck that calls for 51 psi max? Seems like the tires are underflated to me

I have had the truck just over 3 weeks and I am averaging 23 mpg right now. I am hoping my mileage will go up some more since I added some more air. What do you guys think????

Thanks...

 

Do the chalk trick. The write up is somewhere around here but you basically draw a line of chalk across the tread then drive about 100 feet then check the wear. It should be even across the entire tread.

 

I run mine at 34 up front and 32 in the rear. Do the chalk method man.

 

I did see the chalk method when I was searching....thanks

 

I don't follow the recommended pressure. My tires are max rated at 44PSI, but I set them at 35.
The door jam tag states 29PSI; I tried that once and they looked too soft.

 

35psi. all around works well for me. My door jam states 29. This is way too low in my opinion.

 

The chalk line test has already been mentioned- It's the way to go. That doorjamb pressure only works with the OEM tires for one thing. And it's made to compromise about wear and gas mileage. You can use that as a starting point but getting solid wear pattern info from the chalk line test is the way to go.

 

I can look at a flat tire and tell the pressure is no good.

 

Door jam unless you load the truck beyond capacity and then use the max. tire pressure so they don't fail... sure your truck is now messed up, but your tires will be fine!

Seriously, each of our trucks has the correct pressure for THAT truck with the supplied tires. My truck is a 4WD DC and the door jam says 29 front and 32 rear and the BFGs have a max. of 35 psi on the sidewall. That's not a lot more than the Toyota spec wants...

Now, on my last truck (same model), I tried the Cooper STT Mud Terrain 3 ply sidewall tires and if they were much below 40 psi, they were sloshy on the road... I think they had a 55 psi max. rate. So, if you change the type of tire from the original, you may need to customize the pressure.

 

You're absolutely correct.
I feel better setting the pressure where I do. The tires appear fully inflated, are well within the rated spec, and the truck rides and handles great. I may try this chalk test, though, to see where I stand.

 

Just received my Hankooks and love them. They came from the installer with 32 lbs in each tire. They definitely look under inflated. According to Hankook's website for optimum performance they should have 90% of the maximum PSI which is 44 PSI. This equates out to 39.6 PSI. I would like to get the most for what was paid for these and will give this a try. Hopefully the ride will not be sacrificed.