Toyo A/T 305/55/20: What PSI should I run?

[chixdigit]

I'm confused because the tires say to run much higher pressure than what is on the door sticker for the truck. I realized that my truck came with different tires, and that listed PSI is for THOSE tires, but why such a difference?
I am running 40psi cause the guy at Discount Tire said that running much more than that might cause my TPMS to light up- due to TOO much pressure.
BUT, I want to get the best tire wear/ mileage possible also..
Anyone have any input on my 2 concerns?
Why such a PSI diff between stock and Toyo tires? and
What psi are you running/ recommending, and why?
Thanks..

[Big_Al1]

Well I got 295/45/20 I run 38 in mine 40 was a harsh ride for me I would try using the chalk test do a search this will give you the best pressure for long term wear.

[chixdigit]

Thanks for the reply... I found Rone's (if I remember correctly) thread about the chalk test, but I have not had a chance to get around to doing it. The thread was a very informative one for me though. Thanks.

Can anyone else please just chime in with the psi that you run if you have this same type of LT tire in this size?
I checked mine last night and they were actually at 38psi. I saw on that same thread that you should run higher psi's in these LT tires (as opposed to the base p-metric tires that come with these trucks), so I took it up to 44 in the rear, and 45 in front. I can tell it is a bit stiffer ride. But it is better for the sidewalls of this type of "higher pressure tire" and will it give me better mileage?
Thoughts anyone?
What pressures are you others with this tire running????

[DevinSixtySeven]

The pressure listed on the sidewall is the maximum pressure for which the tire is rated...or to put it another way, if you were to load each corner to the maximum load rating for that tire, you'd need that much pressure to properly support it.

So working directly from that statement, the proper pressure for each axle depends on how much load is over that axle. I don't worry about the side to side difference, but you could if you wanted.

The other test you can do is the heat test. Inflate the tires to the door pressure, then go drive around for a few minutes. Take the pressure in each tire, and if it's more than 10% greater than the cold measurement, add a pound to each tire and do it again. Repeat! You'll find the temperature goes down as you reach a safe long-term pressure, and thus the pressure difference between cold and hot measurements.

Then do the chalk test when you get around to it. If they come out wildly different, side with the heat test.

Overinflation doesn't just cause a stiff ride, it causes poor handling, so be wary of overinflation just as much as underinflation. You'll lose traction more readily in rain and on ice, and snow will be hopeless.

-Sean

[chixdigit]

Thanks Sean.. It was YOU that wrote that great info (that I realy learned from) on the post that I read after my search). Thanks for the good info.
Honestly, the heat test seems to be even more of a pain than the chalk test! Makes perfect sense, but I will never get around to it..
I totally agree with the overinflation/ traction aspect too..
I drive my truck un-loaded 95% of the time.. do you think that running 45f/44r on my tire is too high? It IS rated up to 65- loaded..

[DevinSixtySeven]

Originally Posted by chixdigit

I drive my truck un-loaded 95% of the time.. do you think that running 45f/44r on my tire is too high? It IS rated up to 65- loaded..

Unfortunately you're the only one who can answer that, with those two tests...otherwise you're guessing.

If I overinflate by two pounds I can tell LOL. Underinflation is harder to feel if it's only a pound or two, but the sidewall heats like mad.