What psi should i run?

I have the exact same tire and use the info by Toyo...
I run 37 psi front and rear cold

 

Thanks, I'm probably just reading stuff wrong or not following their examples exactly, but you got me more on track anyway!

 

No problem...

The stock Offroad tire is a ISO/ERTRO/euro-metric 265/70/16/112 SL. Notice there is no P prefix on the stock tire. You need to use the chart on page 28 to find the weight. A standard load(SL) rating of 112 @ 30 psi gives us a weight of 2,149 lbs.


Dividing 2,149 by 1.1 gives us 1,954.

So...
P-metric and ISO/ERTRO/euro-metric tires require a psi capable of supporting 2,149 lbs, no matter the size or load rating.
LT-metric and LT flotation tires require a psi capable of supporting 1,954 lbs, no matter the size or load rating.

IMO, we should never compare psi with someone else; it tells us nothing comparatively speaking. Instead, it makes more sense to say, I inflate to "X" amount of weight and weigh "X" amount over curb weight.

Since you chose a LT265/75/16/123(E)...


...your target weight is in between 35 and 40 psi.
We have to extrapolate a value for 1 psi between 35 and 40 psi.
2,100-1,910=190 lbs
190 lbs=5 psi
38lbs=1psi

35 psi(1,910 lbs) + 2 psi(76 lbs)= 37 psi(1,986 lbs)


I'm in Rogers, by the way.

 

Thanks, that is exactly what I needed -- hard to get the formula right if your starting place is incorrect. I had the rest of it the same, just started in the wrong place. This is a great reference for this thread!

I agree. And at 37psi, they are perfectly capable of handling the GVWR. Stuff adds up quickly, and I am not even heavily armored. Without camping supplies (but with RTT and rack), I'm probably about 700 lbs. over curb weight with me and the dog included.

Trying 38 for now (well, my automatic inflator was set to 38, other digital gauge says 37, so close enough).

 

Question - I have new Wildpeaks when cold are at 32 psi. Once they are warmed up they go to 37/38 psi. Is the increase figured in to the start pressure? To me I'm running 37/38 psi because that's what they run at 95% of the time. I'm sure there is a simple logical answer to this and I'm over thinking it.

 

Alway measure cold; tire heat and rising ambient temp will increase psi.
2 rules of of thumb are; (1) 1 psi increase/decrease for every 10 degrees and (2) no more than 10% increase due to tire heat.
If you're seeing more than 10% you might be under inflated.

What size and load rating are you running?

 

285/75/R16 E

That's the way I have always read the tire pressure (cold). I was very surprised when there was such a jump. It has been warm here in SoCal so maybe that is why the larger jump then what I would expected. Having said that is the theory set/check pressure cold so that is the lowest pressure they will be?

 

Yes.

Looks like you're getting lows in the 70s, highs in the 100s; a 30 degree ambient temperature swing is 'worth' 3 psi.
Now you're at 34-35 psi. With a cold psi of 32, you should have a tire heat swing of 2-3 psi; within the 10% rule.

A measure of tire heat swing is cold vs at least 10 minutes at highway speeds, with constant ambient temperature.

Heat swing is a two part thing; ambient swing and tire heat swing(from friction and deflection when driven).
If you're comparing cold sitting vs max ambient temp + max tire heat, it might seem like a big difference.

 

Sorry for late reply as I wanted to test pressure and temps today. Started with an outside temp of 71 (by the beach so much cooler) pressure was 32. Drove 30 miles inland where the temp was 93 pressure ended up at 36. Seems a bit high based on the calculations but I guess its not anything to worry about.

 

I don't think it's high at all.
32 psi at 71° is expected to be 34 psi at 93°.
If you're at 36 psi, your 'tire heat' is only 2 psi. 2 out 32 is 6.25%.

 

I usually run my tires about 5 PSI over the mid-range of the rating. Works for me...

 

It looks like I'm within specs so that's good news. I appreciate the help and explaining the numbers.

 

I'm running 285/70r17 and even after rotation and setting cold psi to 36 for all four tires, I still start out the morning around 32-33 and by the time I finish my 41mi drive into work I'm usually around 37 all around.

I need to chalk test them, but don't have many concrete straight and level area to test them out (used to do them at a shutdown shopping lot...but I don't want to have to get into a shootout just to get optimal psi!

 

I would like to do the chalk method as well but finding a good location can be a challenge.

 

265/70/17 G2s.... 35psi good on a stock 2019 OR?

 

28 psi in your new tire is equivalent to, 29 psi in an OEM Sport tire or 30 psi in an OEM Offroad tire

 

I just purchased a used 2014 2.7L Tacoma Regular Cab 4x4 Automatic. The truck has a 6” ProComp lift with 18x12 Moto Metal wheels and 305/70 18 (35s) Mud Hog M/T tires. The tires are in good shape and only 6 months old. The truck has aftermarket front and rear bumpers with 10k winch. Max tire psi is 65 cold and Toyota door trim recommend psi is 30.
What should I run the psi on the street?

https://2014tacoma.shutterfly.com/

I’m new to the lifted truck big tire world. Any help would be much appreciated.

 

Those are big tires...
As much as I dislike the method, I'd chalk them and start at 30 psi. My guess is you end up somewhere in the 25-30 psi range.

 

Thanks for the info splitbolt. I’ll get the truck out this week and chalk them. Does it matter if the tires are cold or should I do some driving to get them up to temp before doing the chalk test? Thanks again

 

Cold.