What tire pressure for E-rated tires?

KyFJGuy [OP] · 07-09-2011, 05:23 PM

I was wondering what you all are running for tire pressure on your E-rated
AT tires. Looking for some recommendations on how much air to run in them.
Currently running about 35 psi and they seem ok, but was wondering if that was enough. How is the highway ride at 40 psi compared to 35 psi?

KyFJGuy

**brianh** · 07-09-2011, 06:40 PM

35 should be pretty close. You want to run the right tire pressure so you get a good, even contact patch on the ground. The best way I know is to park on a pretty level street and use a piece of chalk to draw a line across the width of the tires. Then drive in a straight line for at least a few tire revolutions. If the chalk is worn off all the way across, you're at least close. If the chalk wasn't touched on the outsides, your pressure's too high. If it wasn't worn off in the middle, it's too low.

After all that, keep an eye on the wear and same thing applies. More wear on the outside than the center means too low and more wear in the center means too high.

**銀チタン** · 07-09-2011, 06:55 PM

They way I understand it, regardless of the load rating, the OEM door jamb psi recommendation supersedes that of the tire manufacturer.

That said, I believe that Toyota recently upped the psi recommendation, and are reprogramming TPMS sensors at 45psi, and I can't confirm because I'm not near vehicle, but after a recent service, I believe they did to mine.

I'm running a BFG AT 10 ply (e) and have experimented with varying tire pressures from 35 to 60, and found ride quality suffered after 45 psi, dramatically, in my opinion.

**brianh** · 07-09-2011, 07:05 PM

Higher pressure will help gas mileage a little but if your tires wear out too soon it takes away any savings in fuel. The door jamb sticker is a good place to start but an e-rated tire is usually stiffer and may need less pressure to give an even contact patch.

football751 · 07-14-2011, 11:40 AM

Quote:

Chris Delancy previously said:

That said, I believe that Toyota recently upped the psi recommendation, and are reprogramming TPMS sensors at 45psi, and I can't confirm because I'm not near vehicle, but after a recent service, I believe they did to mine.

The stock FJ tires aren't rated for pressure that high, they're rated for either 32 or 35 psi.

I run my KM2 255/80/17 (E rated) at 40 psi and haven't had an problem. May try going down to 37, but I've had them for over a year and 40's been good to me.

Metro Billy Man · 07-14-2011, 12:26 PM

I run 32 on road (MTs)

14 to 30 off road

SWutah · 07-14-2011, 02:11 PM

I run 42# good contact patch and not to hard.

Potato Launcher · 07-14-2011, 02:16 PM

Quote:

SWutah previously said:

I run 42# good contact patch and not to hard.

Running 42# as well on 285 KM2's, not too soft but not too hard either.

***mikey*** · 07-14-2011, 02:27 PM

36 psi

**Woodsman** · 07-14-2011, 05:10 PM

Running LT285/70R17E Nitto Terra Grapplers.

They feel good and wear nicely at 35PSI. However, on long trips out to Colorado/Utah I often run them closer to 38PSI because I generally have extra weight along and it gives a touch less rolling resistance.

I think I can tell the difference in ride from 35 to 38 as expansion joints are more pronounced. I have driven with them as high as 45PSI and the ride was akin to my old '64 Falcon on narrow bias ply tires. NOT good or safe. Hard tires tend to pull you into "grooves" and offer a little less contact patch.