Tire Pressure

[AnthonyMV]

Did a search. Didnt find any thread topics with this title.
Question is, what tire pressure is everyone here filling up to?
33,36,38,40 psi ???
id like to know, since im still kinda messing around with the steering wheel shimmy (got new kumho kl61's the other day-gonna bring truck to work and deflate all the tires to refill em with nitrogen).....
i'd also like to find out how much,if so, the higher tire pressure is helping with mpg.
All responses are greatly appreciated.

Thx
Anthony

 

[RubiconSS]

May I ask what Load Range? Are they "E"s?

 

[scanny]

on old P-tires I kept 34-35 psi, on LT it's 36-39 psi.

 

[1engineer]

Did a search. Didnt find any thread topics with this title.
Question is, what tire pressure is everyone here filling up to?
33,36,38,40 psi ???
id like to know, since im still kinda messing around with the steering wheel shimmy (got new kumho kl61's the other day-gonna bring truck to work and deflate all the tires to refill em with nitrogen).....
i'd also like to find out how much,if so, the higher tire pressure is helping with mpg.
All responses are greatly appreciated.

Thx
Anthony

Well,
I had the shimmy originally with the OEM tires and found that my tires had 44 psi from the dealer. I did many tests and determined that 35 psi got rid of shimmy and "wandering" on the road. Fast forward 30K miles and I got Cooper AT3 AT tires in P load rating. 37 psi is where they do well. I did a quick chalk test to make sure full tread was in contact and after 10K they are wearing fine.

You have read about the nitrogen nonsense in the tires right? Unless you are racing the 4Runner it is a waste of time.

 

[RubiconSS]

Run 40psi in my "E" load LT's. Stiffer the sidewall the more air you need to keep the contact patch from going concave and riding on the outer 2" of the tire edges because the sidewalls are so stiff and the truck just isn't heavy enough.
As Engineer said, the chalk test is a good way of telling and you can slip a business card under the edge as well and inflate until you can't pull it out.
Rule of thumb for me;
"E" load - 40psi
"C-D" - 36-38 psi
Pmetric - 32-34
I tried the Nitrogen but went to Helium now I can't seem to keep the front end from floating.

 

[AnthonyMV]

thx 4 the responses

Well,
I had the shimmy originally with the OEM tires and found that my tires had 44 psi from the dealer. I did many tests and determined that 35 psi got rid of shimmy and "wandering" on the road. Fast forward 30K miles and I got Cooper AT3 AT tires in P load rating. 37 psi is where they do well. I did a quick chalk test to make sure full tread was in contact and after 10K they are wearing fine.

You have read about the nitrogen nonsense in the tires right? Unless you are racing the 4Runner it is a waste of time.

the nitrogen was going to be used to keep the pressure steady at whatever the tire was being filled to. i think,no?
i have the kumho kl61's.....says "standard load" on the sidewall......P load rating also?

thx
anthony

 

[RubiconSS]

I'd say start at 35 psi and go from ther +/- 2psi balance ride/comfort/handling/MPG

Note: "Free" air is about 80% nitrogen so I guess it depends on what they are charging for the other piece (-:
You said fill er' up at work so maybe NaDa.

 

[WCVanHorne]

the nitrogen was going to be used to keep the pressure steady at whatever the tire was being filled to. i think,no?

Un... No. N2 is pretty much a margin scam for tire places. Costco gives it away with their mounting which is the only time I get it. It probably lowers the leak rate by about a PSI a year. There is far more variation between tire types, mounting, etc. than straight N2 vs air when it comes to pressure loss. It also give a false sense of security to those who never look at their tires (and don't have pressure sensing). Leaks are due to a lot more things than just the somewhat higher permeability of rubber to O2. Rim leaks, valve leaks, slow puncture leaks, etc.

Heck, although I haven't run the numbers, after a year or two of topping up your tire probably has a pretty high percentage of N2 in it anyhow.

Finally I'll bet most places just put N2 in these days anyhow even if you don't pay for it. It's the hose right by the station with the Schrader end on it. Probably more of a PITA for the tech to grab the regular air hose and swap ends.

 

[DannyLlama]

Well,
I had the shimmy originally with the OEM tires and found that my tires had 44 psi from the dealer. I did many tests and determined that 35 psi got rid of shimmy and "wandering" on the road. Fast forward 30K miles and I got Cooper AT3 AT tires in P load rating. 37 psi is where they do well.

Thats good info since I have the same exact tire.
You do this for four tires ?

 

[WCVanHorne]

BTW I just snooped around to find a good debunking reference. This guy seems to have a nice summary to help dispel the N2 FUD:

Nitrogen for Tires: FAQ

 

[MacRunner]

I was researching the same subject and here is a good reference

LT Tires need more tire pressure

Also, make certain you take into account a hot vs cold tire:
Checking pressure when tires are hot:
If pressures are checked after tires have been driven for more than three minutes or more than one mile, (2 km) the tires become hot and the pressures will increase by approximately 4 psi. Therefore when the tire pressure is adjusted under these conditions, it should be increased to a gauge reading of 4 psi greater than the recommended cold inflation pressure.
For Example Only:
Gauge reading of hot tire:..................................32 psi (220 kPa)
If recommended cold inflation pressure is:..........30 psi (205 kPa)
Desired gauge reading of hot tire 30 + 4 psi =...34 psi (205 + 30 = 235 kPa)
Therefore: add 2 psi...........................................(15 kPa)

 

[Koz]

After many years with SUVs I found 40 psi on "P" tires and 55 to 60 psi on "LT" provided the best ride/wear and mpg. Before any negitive comments try these settings.

Koz

 

[Stifler]

32 on my stockers

 

[oakjefferson]

Fast forward 30K miles and I got Cooper AT3 AT tires in P load rating. 37 psi is where they do well. I did a quick chalk test to make sure full tread was in contact and after 10K they are wearing fine.

About to get these, referring to the hot/cold comment below, this is 37 hot?

 

[WV runner]

BFG Rugged Terrains @ 40 PSI. Increased pressure took out some of the floatiness in the front and still rides comfy.

 

[Randyman...]

I also run around 37-40psi on 265/70R17 BFG AT (C load range) on my '13 SR5 4x4. Rides well, and the MPG hit was minimal. I ran the stock tires around 36-37 for the month I had them...

I'm tempted to go a little higher on the BFG's - Anyone experience issues with premature center-wear (ballooning) with higher PSI's? (koz)?

 

[flyrv9]

Nitrogen is a little more stable to temp changes than air in a tire; but if you check your tire pressure, with a good gauge, often - don't waste your money. Nitrogen is used in aircraft tires not because of stable pressure, but because it doesn't aid in combustion like air does.

 

[psiems]

I run 45 PSI on my "E" rated Duratrac's.

 

[Randyman...]

I'm tempted to go a little higher on the BFG's - Anyone experience issues with premature center-wear (ballooning) with higher PSI's? (koz)?

Bump for Koz or anyone that runs over 40psi over the lifespan of their "C Load" tires - Any issues with premature center-wear due to "ballooning"?

I currently have my "C" range 265/70R17 BFG All-Terrains at 40psi Front/39psi Rear, and it does seem like they have a slight convex curve on the tires' road surface. I'd have to assume this will cause the center to wear pre-maturely? But they handle well, and my MPG hasn't dropped much at all vs. the Stock tires...

I know I ALWAYS ran the 32" BFG All-Terrains at 32-35psi on my old '99 Tacoma (5-6 sets over the 265K I had it), and consistently got 40K miles from a set of All-Terrains. What kind of life-span/Mileage can I expect at 40psi on my new ride before the center becomes bald and causes excessive hydro-planing? I don't mind sacrificing a LITTLE tire lifespan in favor of better MPG and superior handling - but what's the effect of 40+ psi in the long-run? I'm 90 percent highway @ 70MPH if that matters...

Thanks! :hippie:

 

[JB.]

In non-extreme psi ranges, the low psi shoulder, high psi middle wear effects are subtle. I'd expect them to wear better at 40psi and better still at 45 or higher. If you ever were going to get an accelerated center wear then that high percentage of highway use would be the place, but even if you did end up with some slightly accelerated middle wear, I'd bet total mileage out of the tires would still be higher.

If you plan to rotate regularly, there's little risk in trying it. Any uneven wear that might show up would happen slowly enough to be easily addressable with pressure changes. Get a tread depth gauge and put the pressure right where you want it.