Tire pressure question

[bmanning]

Like most of you, I changed out the OE Goodyears on my '97 SR5 (for BFG LT265/70R16 load range D All-Terrains).

Stock, 32psi all around is called for; however, the BFGs are LT (not P-) tires, with a max psi of 65.

Stupidly, I've been running 32psi, not having stopped & thought about it until I read it recently (about LT tires requiring different air pressures than P-).

Those of you who've gone the LT tire route-- what pressures are you having success with? I'm trying 48psi for now...

BManning

 

[02SE]

Just because the tires can handle 65 psi, doesn't mean you need that much air pressure.

The tires you have now, (8 ply) are a much tougher construction, than the OEM wimpy 4 ply tires.

They can support more weight at 32 psi, than the OEM tires.

You can run even less air pressure than you were with the OEM tires, and still have them support the same weight.

I would run them at around 30 psi. Which is probably more than you need, but leaves a nice safety margin, if you don't check your tire pressure regularly.

 

[bmanning]

Now I'm confused...

I'd always operated under the same premise: because of tougher construction, LT tires could handle more weight at the same psi as P-metrics.

I read on another forum that LT tires are a different animal, and should be run at higher pressures because their very design calls for it. In fact, it even said that LT tires can get hot during summer at freeway speeds if they aren't inflated properly (i.e., higher than what's called for on P-metrics).

I realize that maximum pressure is only for maximum loads, but say I'm running my AT's at 32psi...that's half of what they can hold. Makes me wonder if I should be 44, 48psi (something like that) for daily driving and maybe 55psi loaded up for trips.

Sounds like its time for a call to BFG to get their input...I'll let you know.

BManning

 

[lee]

well i have LT tires that im running at 32psi all around....

LT tires can handle more air, yes, but that doesnt mean you should put more air for regular on-road use.

you air down for offroad or sand runs and run at 30-ish for on-road.

 

[bmanning]

Thanks for the input...

BF Goodrich customer service couldn't tell me an exact number, but the young lady did confirm that I should be running higher pressures in an LT tire. But, I certainly haven't had any issues in nearly 10k running between 30-32psi. Confusion.

Solution: I think I'm going to start at 30psi & experiment from there for some miles; maybe try 40psi for a few miles after that to see what feels best. It'll be a lot of experimentation & adjustments, but by doing this I should be able to see exactly what pressure works best for my particular truck & the way I use it.

Sometimes I think too much...

BManning

 

[ebelen1]

I'm new to trucks but had a similar question when I upgraded to 265/75/16 Geolanders AT. I know you're question is around an LT but I can tell you that when my tires were installed, they put the tire pressure at 42 psi. It felt rougher at high speeds and I decided to air down to about 38 psi. The truck seems to handle better with the 38 but I'm considering going lower since Lee goes with 32.

 

[02SE]

Thanks for the input...

BF Goodrich customer service couldn't tell me an exact number, but the young lady did confirm that I should be running higher pressures in an LT tire. But, I certainly haven't had any issues in nearly 10k running between 30-32psi. Confusion.

Solution: I think I'm going to start at 30psi & experiment from there for some miles; maybe try 40psi for a few miles after that to see what feels best. It'll be a lot of experimentation & adjustments, but by doing this I should be able to see exactly what pressure works best for my particular truck & the way I use it.

Sometimes I think too much...

BManning

Those tires can support 2845 lbs. a piece, at 65 psi.

That's 11,380 lbs. total for all 4 tires.

A 3rd gen 4Runner weighs approx. 4000 lbs. Some a little lighter, some a little heavier, depending on drivetrain, and options.

At half their max. inflation pressure they can still support 5690 lbs.

Some person in customer service, may or may not have a clue when it comes to safe loading of tires.

And of course they will err on the very conservative side, because of potential liability concerns.

If they told someone 30 psi, and then that person never bothered to check the air pressure again. Then eventually the tire would lose enough air to be dangerously underinflated.

That's why checking tire pressure regularly, is important.

A load range D tire is intended for a 3/4 ton, or 1 ton truck.

On a light 4Runner, it is overkill.

You can run whatever air pressure you want, but if you run a pressure higher than the low 30's, you're just punishing yourself with a harsh ride, and wearing out the center of the tread faster.

 

[Jason B]

Going from 32 psi to 34, will give you almost 2 mpg more!!!!