285/70/17 SL PSI

So recently got lifted and went up to33s on a 8 1/2 wide wheel

Size 285/70/17 standard load

The installer filled them to 31psi they feel comfortable but seems kinda low. It’s my daily so mostly on pavement. Curious what psi others with this size run and recommendations?

 

35psi

 

Online calculator says 26 for SL but I find that low. I run mine 28-30 PSI and have found that best. Any higher and mine start to crown in the center

 

I have found that the sweet spot (for on road) is 32/33psi.

 

Not to get off topic but what is your wheel width. I've had the same issue on trd or 7.5" wheels. I thought it was because narrower wheels. Because after I installed 8.5" wide wheels I was able to run more pressure without the tires crowning.

 

I also have 285/70/17 SL rated tires. Mine are Falken AT3W and I set mine to 35 PSI. For me, it gives me the best mileage, comfort and control on pavement.

 

I'm on the original offroad wheels so 7.5" wide. It's possible a wider wheel helps prevent crowning at higher pressures - sounds logical.

I also question if it's just the tire design as well. Using the inaccurate fingertip method, the center has deeper tread depth than the edges so it could also be that on my tires

 

Every tire is different. Same goes for every 4runner. With added weight, the right psi will change. But running low psi 30 or less WILL decrease mpg. Thats why I sugguest 35psi. But it truly depends on your 4runner, wheel width and tire.

For me, with a some what light weight and c rated 285s. I run 38psi front and 35psi rear (cold) its working pretty good.

 

I run 35ish psi on 5000lbs TRD Pro and 5060lbs Limited with 285/70R17 SL tires.

 

While I agree that it's OK to adjust from the recommended pressure, this is not a direct comparison.

The OP is asking about SL tires. They require less pressure than LT tires. The same calculator that recommends 26 for SL 285/70/17's will recommend 38 for LT285/70/17's.

30 PSI will definitely not hurt your mileage with SL 285's. OTOH, over-inflated tires will wear unevenly.

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Hmm. The op just says about 285s sl rated tires. Hence why I brought up added weight. I simply sugguested 35 psi has a STARTING POINT. And How does under inflated tires not hurt mpg.

Yes over inflated tires will cause even tire wear. IF your run 10-20 psi over not 5

 

Yes, SL tires. Which is why they would require different pressure than your LT tires.

30 PSI is not under-inflated for the OP's SL 285's. it would be under-inflated for LT 285's.

And, I would consider 35 over-inflated for SL 285/70/17's if the calculator is recommending 26. I'd recommend starting at 26 and adjusting from there. But, I probably wouldn't go any lower than 26.

 

28-30 here.

 

Weight probably is a factor as well but with all the shit I've added I'm pretty heavy and would think if anything, it would need more psi for the load. And agree that all tires are different.

I still think 35 is too high a starting point - maybe start at 32 (original recommended for 265s) and go from there. In the end the OP will have to find their own balance between comfort, mpg, and tire wear. I know mine came installed with 38 psi (I think they assumed they were LT) and that was too high. They rode like rocks and didn't touch almost 1" from each edge of the tire, just the centers

 

They probably went at 38 based on LT tire pressure. It's sad that a tire installer wouldn't know the difference.

I think a mostly stock 4Runner without added weight might be fine at 26 on SL 285's. It does seem low, though.

I'm thinking my next set of "winter " tires are going to be SL, so it'll be interesting to see how much pressure I end up running with so much constant weight.

 

I think with the SL at lower psi you will start feeling sidewall flex, especially with load. I don’t like sidewall flex because it makes me feel unstable, but we all have different needs and thats a good thing.

 

32 psi cold