Tire pressure

I put BFG KO2 load C, stock size tires on my 4R.

The person at Big O Tires said to inflate them to the pressure on the tag at the front drivers side door.

What pressure do you experts recommend for highway driving?

 

44psi

 

Stickers are for tires the same size, load range, and similar tread to OEM.

Anywhere between 32-38.

If you go to a Toyota dealership, whatever primate responsible for rotating your tires will just hook up the compressor until the pressure is in the mid-40s.

 

The discount tire folks recommended and put my KO2 BFGs E-Rated at 40psi. - As already said, you should not follow the door label once you have put something other than OEM replacements on. Be sure not to exceed what is stamped on the side of your updated tires.

 

You should not go with what is stamped on the tire since that is the max pressure.
Use this and figure out what pressure you should be at and adjust it as necessary. S/B 44psi in your case

 

The recommended pressure for stock size LT tires is 44PSI. This is based on GAWR.

I ran stock size LT/C KO2's at 35 and they wore fine. I recommend experimenting, but maybe run at 44 if you're going to be loaded down or towing.

Going by the door is based on the stock load range tires as @LandCruiser mentioned. It's still better than the dipshits who go by the tire's maximum inflation!

 

Beat me to it!

 

I’ve usually run load range E 285/70r17 tires at 35-38 if I’m not loaded up or towing.

They feel kind of bouncy above 40 psi.

 

I ran stock size KO2s in C load for a few years, and repeated chalk test put them at 33 front and 31 rear on an unloaded stock 4R.

 

I appreciate all the answers. I was sure someone was going to jump on me for asking a question already answered

I used the search engine on this site to get an answer but got nothing useful. Then I Googled the question and found a thread here that discusses the issue. So maybe this thread can be merged with that one.

In any case, I thought the answer must be straight forward, but apparently it's not

Again, thank you!

 

I have the KO2’s in load C as well. I found that setting them to 40-41 PSI and having them heat up to around 43-44 PSI while driving was the only way the steering wheel wouldn’t shake (has been discussed ad nauseam and I’ve posted elsewhere about it). If I didn’t have to worry about that, 38 seemed to be about the sweet spot for me.

 

I think the recommended pressure for LT 285's was 38. I don't remember what I actually ran, though. I think 35.

Most of the folks here are pretty cool about answering repeat questions. Probably because we all know that the search feature doesn't always get good results.

Tire pressure is pretty subjective. The recommended pressure for LT tires can feel like way too much. It seems to vary depending on the type of tire, and your load. It seems like basing pressure on your actual load will yield the best results.

 

That Calculator doesn't work me. Our stock size tire 265/70R17 is not listed in the drop down menu. There are only 4 choices in that menu. Am I doing it wrong?

 

The sizes in the drop down menu are examples.

Choose the type that applies and then you can enter your size.



If you're on LT 285/70/17's it will recommend 38 PSI.

 

Ahh that explains it.

 

The calculator gave 38PSI for 285/70/R17 C loads. I tried the chalk test from 34psi to 44psi in 2psi increments and didn't see any difference, so I've settled on 37psi for now.

 

When I used the calculator for my BFG KO2 265/70/17 C load tires I get a pressure of 44 psi. Yet people above get 38 psi for 285/70/17 C load. Does it sound correct that the 285s come out with a lower pressure, or am I doing something wrong?

 

Not an expert but I wheel with guys running 37 inch and 40 inch LT tires. Their PSI is like 9 off road and 20 on road.
So my theory... larger tire = less PSI smaller tire = more PSI. Playing with that calculator just now, that seems to be the case.

 

Yeah, I guess it's Boyle's Law.

 

Like @DRobs said, bigger tire = lower pressure. My LT 295's come out at 35.

Think of it as surface area vs the weight it's supporting. The wider or larger diameter tire has more surface area on the ground, so less pressure per square inch is required.

This is actually a huge factor in the value of larger tires for off-roading. The wider and taller you go, the lower the required PSI. This translates to better flotation, and more surface area to get traction on rocks, dirt, mud, etc.

So, even though my 295/70/17's only add about an inch of clearance, the added traction is worth the trade-off for me. Obviously this won't be the case for everyone, though.

 

I’m surprised that nobody mentioned that you can actually call BFG and they have a calculator for every vehicle. I actually did call when I purchased stock size, load range C KO2’s for my 4Runner. They told me 40psi so that’s what I run.

 

I wonder how they come up with that number? The "proper" pressure for stock size LT tires on our 4Runners is 44. But, most people run them lower than that. Maybe they found 40 to be the sweet spot.

 

BFG told me 40PSI too when I asked them about KO2s in 285/70/17s in C load

 

If they're telling you the same pressure for two different sizes, I wouldn't trust them. 285/70/17 LT's are supposed to be run at 38 on our 4Runners, but I would probably run them a bit lower.

 

Yup. Agreed.

 

Would the sticker on a TRD Pro give you the right tire pressures for the NItto Terra Grapplers? I think it says 32 psi -- but also found that the dealership had overfilled the tires to around 44 psi, which had produced an unusually hard ride -- and since I have been running them at 35 psi cold, which means they get up to 38-39 when driving a reasonable distance.

 

Cooper 275 LT's, we run 38 psi on road, off road is 24-28 psi, this works for us. I did not run through the calculator, but when we had those tires mounted at the dealership, they were set at 46 psi, a bit too hard for a 'nice' ride.

 

The OEM tires are LT not P, right? Or did they just give us P-rated?

 

Japanese Automobile Tire Manufacturers Association and ETRMO European Tire and Rubber Manufacturers Assoc, both state a Minimum Pressure for Load Range E tires of about 46 PSI.

OEM Size (P265/70R17 SL) Load Capacity: 2425 lbs. @ 32 psi.
New Size (LT265/70R17 E) Load Capacity: 2425 lbs. @ 46 psi.

My 2013 FJ Cruiser TT was recalled to put a 46 PSI sticker on the door (stock sticker was 34 PSI), because the stock tires were E-Rated BFG.

You are probably better off with a C-Rated tire and run around 36-38 psi.

 

On my Venture, they were P rated.