E rated tire pressures

[Derek G]

Pick up Duractracs on Friday and went to the trail, noticed the tire shop set them at 45 psi when I went to air down. When I aired up I set it to 32, then changed to 35 front, 32 rear for the front end weight. This seems to be a good set up for me, but I'm curious as to what pressures some of you are running that have had E rated tires on longer.

 

[RallyBud]

Hey folks! I am installing some 275/70r17 BFG AT KO's here shortly and am wondering what others running E rated tires are setting their pressures at?

 

[92-SR5]

It should say on the tire. I think e-rated is around 75psi or something. Personally I like c rated better for off road.

 

[Ohhh S.k. CFPB]

Hey folks! I am installing some 275/70r17 BFG AT KO's here shortly and am wondering what others running E rated tires are setting their pressures at?

running the same tires, im running at 50psi for highway and run down to 30-35 on the trails sometimes lower

 

[92-SR5]

I like to drop mine to 10psi on the trails so e rated isn't the best option for me.

 

[cdrewferd]

I run my Toyo MTs at 30 on road. Only time they've been off road I did 20, but will probably start using 12-15.

 

[JB.]

Pick up Duractracs on Friday and went to the trail, noticed the tire shop set them at 45 psi when I went to air down. When I aired up I set it to 32, then changed to 35 front, 32 rear for the front end weight. This seems to be a good set up for me, but I'm curious as to what pressures some of you are running that have had E rated tires on longer.

I run about 36psi in the cooler months. When it gets hot I bump it up to around 40.

Probably not a bad idea to consider 35psi a minimum (definitely come summer), just on principle. Load tables don't go lower than that for LT tires which should tell you something. The official procedure these days for pressurizing LTs that have been switched from the OEM P type tires of the same size is to add around 10-15psi so as to avoid a reduction in OEM tire load reserve, thus, I assume, the reason the shop set them at 45psi.

Here's something in chart form for more context.

http://www.toyota-4runner.org/engin...s/110299-lt-tires-need-more-air-pressure.html

 

[Jeremy556]

It should say on the tire. I think e-rated is around 75psi or something. Personally I like c rated better for off road.

E tires have a max pressure of 80psi, but should be inflated based on industry load tables. You should never run 80psi in them on a 4runner.

On the same vehicle, in the same size, all LT tires should be inflated to the same pressure, regardless of load rating.

An E rated tire will have a tougher sidewall than the same tire in a C rating, so it will be better for sidewall puncture resistance. The E tire will be heavier and negatively affect performance and MPGs on the road. Both can be aired down for off road use at low speed.

ETA: Read J.B.'s thread.

 

[Titanpat57]

I'm running at 42-44 psi....18 off the road

 

[RallyBud]

Thanks for all the replies. Good info guys...I appreciate it.

JB's thread is what prompted me to ask what pressures guys are typically running. I need to go back and reread it because I am a nug.

I think I will start them out at 40psi and do a chalk test and go from there...sound reasonable?

 

[cbielat]

Whatever the rating of the 285 Duratrac is, I'm running around 42-45 in mine.

 

[JB.]

I think I will start them out at 40psi and do a chalk test and go from there...sound reasonable?

Sounds reasonable, though I think simply paying attention to how the tire is wearing under your personal driving habits is much better than a chalk test. Non-optimum tread wear due to tire pressure happens so slowly that it's easily caught and corrected if reasonable attention is paid to the tires. As you can see in the 3rd chart, 40psi in the 275 would be the equivalent of about 43-44psi for the 265.

 

[eddiebx]

Thanks for all the replies. Good info guys...I appreciate it.

JB's thread is what prompted me to ask what pressures guys are typically running. I need to go back and reread it because I am a nug.

I think I will start them out at 40psi and do a chalk test and go from there...sound reasonable?

Chalk test is kind of worthless IMO, unless you only plan to drive in a straight line for the entire life of the tire, lol.

For example, I set my new LT tires to ~46 psi as a baseline, drove them ~6-7k miles and measured the tread depths all around. Found that my front tires have ~1/32" more shoulder tread wear; and my rear tires have ~1/32" more center tread wear. Rotated front to rear and rear to front, and am going to test it for another few thousand miles to see if it balances out (as I suspect it will).

Point is, if you did the chalk test alone, you might only find that the tires appear "over inflated" all around, but reality is the shoulders of the front tires are experiencing way more scrubbing every single time you turn the wheel.

If you're going for optimum tread wear you probably want to just monitor them every few thousand miles and adjust accordingly. And of course rotate often.

 

[ebg18t]

I'll post this link here. Long discussion with charts.

http://www.toyota-4runner.org/engines-suspension-wheels-tires-audio-accessories/110299-lt-tires-need-more-air-pressure.html

 

[eddiebx]

I run about 36psi in the cooler months. When it gets hot I bump it up to around 40.

Probably not a bad idea to consider 35psi a minimum (definitely come summer), just on principle. Load tables don't go lower than that for LT tires which should tell you something. The official procedure these days for pressurizing LTs that have been switched from the OEM P type tires of the same size is to add around 10-15psi so as to avoid a reduction in OEM tire load reserve, thus, I assume, the reason the shop set them at 45psi.

Here's something in chart form for more context.

http://www.toyota-4runner.org/engin...s/110299-lt-tires-need-more-air-pressure.html

I'll post this link here. Long discussion with charts.

http://www.toyota-4runner.org/engines-suspension-wheels-tires-audio-accessories/110299-lt-tires-need-more-air-pressure.html

:gossip:

 

[CenCalifoothill15]

I'm also running Duratracs 285 E-rated tires

*On trails I air down to 15psi
*On road/DD I'm running 36psi

 

[RallyBud]

I contacted BFG to see what they recommend just for shits and giggles. Their response was:

"We appreciate you purchasing LT275/70R17 All Terrain T/A KO tires.

We recommend using 38 psi, measured when the tires are cold for the proper load capacity for your vehicle."

 

[Canazes9]

I'm running 42 psi in my wife's 5th Gen w/ 265/70r17E Mickey Thompson MTZ's. Rotate regularly, wear is even. Off-road I routinely run 14-16psi, though I have had them down to 12psi.

David

 

[Muddy Duck]

I took this question to the manufacturer and here is Michelin's response:

I drive a 2010 Toyota 4Runner which originally came with P265/70R17 tires and Toyota recommends 32psi for these tires. I now have LT265/70/R17 (E Rated) Michelin LTX M/S2's. Should they be inflated to a different pressure? The GVWR is 6300lbs. Also? Should I increase the pressure when towing a 4000lb trailer? Any help would be appreciated.

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When installing a different size than the original equipment tire, all vehicle manufacturer specifications must be maintained. The replacement tire should be inflated to provide the same load capability of the original tire size at the manufacturer’s recommended pressure. By changing to the LT rated tire your pressures should now be at 50PSI. You do not need to change the pressures for extra loads or towing.

 

[1blink]

I ran my e rated 265/75/16 GY silent armor tires at 42psi for the first 25,000 miles. There is noticeably more wear in the center of the tires, suggesting to me that the pressure was too high. I backed it off to 35psi as a result.