What tire pressure for my 265 70R17s?

32 psi

/thread

 

I would think you might be putting unnecessary wear and tear on your suspension components running 80 psi unloaded. You'll be running Flintstone style on rock solid tires.
We haul tons of glass on full size trucks at work and don't run our tire pressure that high.

 

I run 40

 

40 unloaded. 45 front 50 rear with my camper mounted.

E rated requires more air than P, not less.

 

I didn't see any discussion on Michelin LTX M/S 2's. I'm running my 265/65/17 at 32 all around. Anyone else have different ideas.

 

Your not only sacrificing your ride but also Sacrificing your tire life. For best wear and functionality DO NOT Fill your tires to the max psi on the side wall.

 

I run my MS2's at 36 rear, 34 front, cold. For the most part, it keeps me happy year round here in SD with big ambient temp variation (-30F° to +100°F). Due to ambient temp, it gives or takes a little and matches well with my seasonal use (more highway summer and more ice/snow winter). They seem to lose more in winter than they gain in summer. Ive always maintained that the front is a little lower cold pressure due to the increased heat generated while driving (friction from front end weight causes the front tires to heat and expand more than the rear). Measuring hot pressure they are almost the same.

 

^ ^

Thanks for your reply.

 

When you park do your front tire appear more inflated then the back then? I run 34 front 30 back and even after a long drive my back tires are more inflated.. I should probably reduce my rear pressure.

 

Honestly, they always look about the same to me. Never really notice a visible difference, but ive never really paid attention either. Maybe because the back end is so much lighter, it responds to an increase in pressure differently-- Add two pounds to the back and its gonna rise more than if you add two pounds in the front? That would be my guess. These tires are FAT when uninflated. Have to imagine both upward and outward expansion. And i bet different areas on the tire stretch more than others. Anything more than a 4-5lb difference front/rear sounds loke a lot to me, but i could be wrong.

 

Just curious- is 34/30 hot or cold?

 

Cold. Such as sitting in the drive way over night and being checked in the morning.

 

I guess any tire I have ran you can always visually get a good idea if a tire is under or over inflated. Being over inflated puts more pressure on the center of the tread which will result in premature tire wear. Since you have much more weight on the front tires they need more pressure to hold the same shape. Anytime I have gone on a drive and checked my pressure the front and back go up about the same in psi. Usually 2-4 psi it seems on both. Just my experience and opinion..

 

I run 40 for DD, that's 50% of the max psi. I air down to 30 on long bumpy drives, and to 20 for situations which require high traction. The numbers get fudged a bit for other factors.

If I ran 80 psi...

 

34 Front and 32 Rear . Original BFGoodrich Rugged Trail T/A Tires.

 

Here is a Load Inflation Table from Toyo. Covers most P Metric and LT Tire sizes. Look up your tire and it will give you the recommended pressure for the weight of your vehicle. Set them up and then do a chalk test to make sure they are going to wear right. Only goes down to 35psi for LT tires (most likely because of heat issues with LT's at lower pressures).

 

Just to be clear, even though most people know this, tires do NOT have a recommended pressure on the side of them. They DO have a max cold pressure rating. Most people will never need to run a tire at max pressure. Especially on a Tacoma.

On certain tires, you can exceed the max pressure on the tire, but at the expense of speed. Here is an example from goodyear: http://www.goodyeartrucktires.com/pdf/resources/publications/2010_loadinflation.pdf

Tire pressure needed is related to actual truck weight, regardless of the tires weight rating. A C rated and E rated tire of the same size and design will be rated for the same weight at the same PSI. As PSI goes up, so does the weight rating. An E rated tire can hold a much higher PSI than a C rated tire, so therefore has a higher weight rating.


Also, many vehicles have a recommended tire pressure based on the GVWR or GAWR. For a truck like the Tacoma, this might be pretty close for every day driving. For a one ton dually that sees very little real work, it will call for a PSI well above what is needed. If you operate your truck at a weight well below the GVWR, you will probably see your chalk test call for less pressure than the factory recommends, or higher if you are heavier than the GVWR.