QuestionQUESTION: have a 2005 dodge ram 1500 came with p265 70 17 where I drive my truck the tires don't hold up. I went with the Nitto trail grappler in 255 75 17. the door says 35 psi , with the new ties what should the new psi be. thanks
ANSWER: Brent,
Just for future reference, that actual size of the Nitto's is LT255/75R17 - the letters are important!
On every vehicle sold in the US - and I understand this is a worldwide practice as well - there is a sticker – commonly called the vehicle 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.
According to Tire Guides, the vehicle tire placard of a 2005 Dodge Ram 1500 with P265/70R17's ought to say the inflation pressure should be 35 psi. Please check this as the next step depends on this being correct.
In order to carry the same load as a p265/70R17 does at 35 psi, an LT255/75r17 needs to use 50 psi.
Because of this increase in inflation pressure, I am not a fan of replacing P type tires with LT type tires.
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QUESTION: What I am
Most worried about is even tread wear and heat build up as I only put on 8,00iles a year but travel alot of gravel ruff roads and some road trips around 500 miles
Each way.when u say load carring are u referring to empty or loaded if 50 psi what I need to run then that's what I'll run. Just what to have the right psi on the highway
AnswerBrent,
I was referring to fully loaded - which is the way the vehicle placard pressure is done.
But don't worry about even wear. The footprint of radial tires is only minorly affected by load vs inflation pressure. To get even wear, you need to rotate regularly as steer tires tend to wear on the shoulders and drive tires tend to wear in the center - and this is much more dramatic than the affect inflation pressure has on wear.
