What pressure are you running on???

[pistolpete]

Just curious what everyone is running out there....I have the 17" wheels on my 2004 Tundra Double cab and noticed one of the tires a bit low the other day....when I went to check the spec on the tire said maximum pressure of 51psi! but when you check the specs posted on the door jamb sticker it states 29 for the front and 32 for the back......seems like a BIG discrepancy!.....what is everyone else running?

[Rlockyer]

About 5psi less than the number stamped on the tire, but never less than 35psi.

[pistolpete]

Originally Posted by Rlockyer

About 5psi less than the number stamped on the tire, but never less than 35psi.

so you are running about 45-46psi eh???

[H2O_MAN]

35 - 40 psi depending on the load.

[Rlockyer]

Originally Posted by pistolpete

so you are running about 45-46psi eh???

With your tires, I would. My Cross-Terrains are rated to 35, so that's where they run.
I used to run the Sears 30k-warranty cheapies on my Escort at 44 and I'd get 70k out of them if I was religious about rotation and balancing... the '91 Escort absolutely ate rear tires.

The factory 29/32 is intended to offer the best compromise of ride quality and safety, while maintaining offroad traction.

Lower pressure is more comfortable
Lower pressure grips sand, mud, and rocks better.
Higher pressure runs cooler.
Higher pressure increases the speed at which you will start to hydroplane.

[jim65wagon]

I ran my Rugged Trails at the max (35?) and I run the AT's at 38 for daily driving.

[dezert_rida]

On my 2wd acess cab, i run 35psi at all 4s, on BFG AT 265-70-16s on stock rims.

If im towing a car hauler with the prerunner on the back the rear tires get 50psi.

[jeshoffstall]

On my DC I have noticed that I get a better ride, better control, etc. when I run at the door-sticker recommended 32PSI in the front and 33PSI in the rear. (16" wheels w/TRD). I just had my first oil change and the techs jacked up the tires to 36psi (yes, it was the dealer)- I could immediately tell the difference- more bounce and sway. Probably not the best solution for tire wear and MPG, but I assume Toyota has spent more money researching tire pressure than I will ever spend in gas.

My .02

[KLS]

35 front
32 rear

40 in all when towing


Ken

[fooddude]

I'm at the stock psi right now(F-26/R-29), but it feels way too soft and looks totally visable that the front tires appear to be under-inflated(kinda looks low on air). A lot of people tell me that too, I always check the pressure and it's at the "door jam recommended" specs.

..but, In my past cars, I notice better gas mileage when the air pressure is slightly higher(maybe 2-4 psi higher) than factory specs..of course, the trade off would be worse all around traction.

Why did Toyota put such low numbers for the recommended psi on the doorjam? Off-road mixed with street perfomance maybe?

I'm thinkin of raising my tire pressures up(stock rugged trails 265/70-16 on an AC).

What should I raise it to?

[Ryone]

There's a big difference between the MAX COLD PSI on the sidewall of your tires and the RECOMMENDED PSI on your door jam. Never inflate tires to max cold pressure. The pressure in your tires increases when you drive on them... remember the Ideal Gas Law? Increase in temperature equals increase in pressure.

KLS was right... 35 front, 32 rear, 40 when towing.
More psi in the fronts because they're supporting more weight.

Ryan

[Rlockyer]

Originally Posted by Ryone

There's a big difference between the MAX COLD PSI on the sidewall of your tires and the RECOMMENDED PSI on your door jam.

Sometimes, sometimes not. I used to run tires rated to 44psi on my Escort, but haven't bought a tire for either my '94 p/u or Tundra rated higher than 35.

Never inflate tires to max cold pressure.

Why not?

The pressure in your tires increases when you drive on them... remember the Ideal Gas Law? Increase in temperature equals increase in pressure.

So what? The tire's rating is max cold pressure. It was designed to handle the pressure increase when warm. IOTW, the max cold pressure is de-rated. You're not going to blow a tire from overinflation by going to max cold.

Advantages to going to max cold:
Best gas mileage: Simple... less rolling resistance.
Possibly best tire wear: I used to run Sears cheapies to 70k on my Escort. Tire wear is also reduced by reduced operating temperatures (which also reduces the delta-p).
Higher resistance to hydroplaning: This one isn't so simple and is often misunderstood, but according to Navy studies at Pax River, the speed of the onset of hydroplaning, at a given depth of water (per mm of tread depth) is solely dependent upon the inflation pressure. What that means for us is that a tire inflated to 28psi will begin to hydroplane at about 55mph. Pushing to 32 bumps that to the 60-65. Going to 35 goes to the 65-70mph range (I can't find the actual formula right now).

Disadvantages to going to max cold:
Possible increase in tire wear in center of tread: Most likely to encounter this on the rears of a Tundra if you rarely haul a load. Easy... get a gauge and measure tread depth every month. If you notice the center getting more wear (I never have), drop the inflation a touch.
Worse ride: Hey.. these are trucks. For trucks they have a very nice ride, and even at 44psi they ride better than some cars.

I'm not completely sold on higher inflation pressures causing a reduction in dry traction. There is less rolling resistance, so I suppose it is possible, but I've only had my ABS kick in on dry, non-frozen pavement once, and that was a two-footed panic stop that resulted in my fender parting company with the truck.

So we've got three possible disadvantages... one subjective, one easily adjusted away, and one possible serious concern. For me, the advantages outweigh the disadvantages.

[dsconstructs]

[QUOTE=Rlockyer]Sometimes, sometimes not. I used to run tires rated to 44psi on my Escort, but haven't bought a tire for either my '94 p/u or Tundra rated higher than 35.


That just made me go look at my tires, rated for max cold 65 psi. Currently running 36 all around.

[Rlockyer]

Originally Posted by dsconstructs

That just made me go look at my tires, rated for max cold 65 psi. Currently running 36 all around.

Wow.
Load range C "LT" tires? Last time I saw a 65 rating was on a '85 Chevy 3500 wearing 12.00x16.5 on a split rim.

[dsconstructs]

Load range "D" LTs. Pretty heavy tires, and heavy AR rims as well. No wonders how I killed my mileage huh?