tire pressure on Nitto Ridge Grapplers

Hey guys what are you running for tire pressure on 265 70 17 Ridge Grapplers for the highway? I am at 38 psi

 

I run 32 psi on my 285/70r17

 

On my 265 70 17 ridge grapplers I am at 38 psi as well. That's what the tire shop recommended.

 

38 here which was recommended on mine by the tire shop.

 

Really nice lookin' truck.

 

I do 30 psi "as recommended by Toyota", not some tire shop.....

But to be honest I do 32 in the winter, due to the fluctuation in our weather here.

 

Same size different tire runs at 32-33 psi... dont listen to shops or Toyota, breakout the sidewalk chalk and test your tires so you know what works best for the tire... also remember that pressure changes with temperature so as temp fluctuates make sure your operating tire is whats right

https://www.youtube.com/watch?v=ojGsavK0Uwc

 

I run 32 in rear and 34 up front

 

Putting chalk on your tires will do nothing more than leave neat patterns on your driveway. That is shade tree technology at it's finest and is not scientific. Don't waste your time.

 

Supported by Tire Companies - https://www.intercotire.com/using_chalk_method_determining_psi
Supported by large off-road vendors - https://www.4wheelparts.com/a/tire-wheel-package-guide-tire-pressure-checker

Care to explain your assertion?

 

If you read the disclaimer from interco, they admit that it isn't scientific and are just repeating something that is of internet legend. As for the 4wheelparts, I don't think that there is need to explain anything from them.

There are several reason that the chalk test is pointless. You have to understand the changing road dynamics to see that it provides no valuable feedback. The most obvious being that you are not replicating driving experience. You see your tires change shape as you drive. The wider the tire and the higher the speed, the greater the distortion. You can see this for yourself if you put a little water in a balloon and blow it up. The balloon will have a specific shape. Now take that balloon by the knot and spin it around. You will see the shape change the faster you spin becoming more elongated. The same thing happens to the center of your tread as your tires rotate. Putting chalk on your tires and rolling around a parking lot won't replicate this.

Let's keep going with another factor, steel belting. Why did we put steel in tires? Simple to keep them flat. Steel belts have a huge advantage over the bias ply tires of old in terms of strength. This allows them to lay flat at higher speeds, but also has a positive/negative effect that they will stay flat over greater pressure ranges. Have you ever notice that your contact patch changes very little regardless of the amount of air you put in them? This makes this chalk nonsense even less effective.

Now let's consider another factor, your wheel alignment. Most alignments on rear wheel drive vehicles will have positive toe in a static position. Positive toe means that it is toed in. The reason you do this is because at speed (see the a common theme here?) the wheels will open up allowing your toe to go to zero. If you chalk your tires and drive at slow speed, the chalk will rub off from the alignment, and not the pressure.

There are probably more reasons that chalk is little more than a gimmick, but it clearly is not scientific. You won't see Nascar or Formula 1 stealing their kids chalk because it simply doesn't work. If you are really a geek about your tires, the way you would do this would be with a temperature gauge like the pros do.

Short of doing that, you really don't need a lot of thought into what you run. Tire brands or sizes have no impact on the pressure you run. My suggestion for tire pressure is that you should never run a pressure lower than what is posted on your placard and never run more than what is posted on the sidewall. What you run in between those numbers really comes down to what is comfortable for you. There are pluses and minuses to going low or going high. You go high, the ride gets more harsh, but you get better road feel and handling. Go toward the lower end and the ride is more comfortable, but you may feel like you are a boat captain.

 

Also - just for some other math based ideas - here is some more support - go to - https://www.toyotires.com/tires-101/tire-load-and-inflation-tables and download the Inflation Load Index document

cut to P265/70R16 which will show a bolded 35 psi as the indicated pressure at 2403 lbs which is just under our load index of the Goodyear Kevlar at 2469 that is OE drop the load by the 1.1 factor for the ratings and you get 2245 or roughly 33 psi... now jump down to LT265/70R17 and see that to get to a similar load index of 2245 you would be under 45 psi. Point being, there is a definite change as you change size and loads and etc... if you watch tire wear, you'll learn what you need to need

 

I highly doubt a Toyota dealer would have a better idea of what Nitto tires should be set at compared to an independent tire shop who has actually sold a few of those tires. Also, the door jam specs are for stock tires.

 

I run 30 cold with nitrogen. I never see my pressure below 29 and I see it maybe sometimes reach 33.im running nitto open country at2 SL rating for the past 5k miles and no issues or abnormal tire wear.

 

Toyota engineer would have a much better idea over a tire jockey, sorry.

 

There are no Toyota engineers at the dealership. And i doubt they called one of theirs up to get an answer on a tire they don’t deal with. I think you have put more faith in a dealership than all of us in here combined ha

 

also - not only did the OP change tire size, he changed load... truck went from 265/70R16 P-Metric to an LT 265/70R17

 

He said recommended by Toyota, not the dealer. Open your manual up or check the door jam sticker for recommended PSI vice arguing for the sake of arguing.

Inflate to 30-34 PSI and you’ll be fine since they’ll inflate a little more as your tires warm up.

 

Guys and Gals, the recommended tire pressure from Toyota inside the door jam is ONLY if you are running P Metric tires with the same specs as the OEM tires. Once you change that label is pointless. The next thing to consider is the Load on the tire with GVRW. Every tire manufacturer has this documented what pressure their tire needs to be for the load it is going to be used on. Match that with the load you have. Period. No chalk, No seat of the pants feel etc. It is literally science.

 

Ah, so he called up Toyota hotline to ask them? Or shot Toyota corporate an email? (sarcastic)

Yeah, that door jam sticker is for stock P rated tires... not aftermarket larger tires with a different ply rating. As nettleberger said he went from 265/70R16 P-Metric to an LT 265/70R17. That is why i said earlier that the door jam is for what tires the rig comes with from the factory.

Edit: ChrisK7UND beat me to it ha