Tire pressure

[DieselDixon]

What are you guys running your tire pressure at when unloaded? I still have the stock tires on.

Thanks

[Lone Eagle]

I got very even wear on all four running 55 front and 45 rear. I just replaced mine at 36K. They had 6/32" left. Later! Frank :D

[DieselDixon]

Thanks Lone Eagle,

Guess no one else is running stock tires. I have been running mine at 50 front and 45 rear, but my fronts only have 6k on them and are wearing funny. Figure I would see what the rest are running them at. I'm going to rotate them today.

[Flyboy]

I run mine the same as lone eagle empty. With a load, I bring them up to 75 or 80. I have 37K on stock tires and still have some wear left. Will replace them with 265's.
Gerald

[bobojay]

28k miles, lots of tread left. 45f/40r unloaded, 55f/65r pulling our 5th wheel. X Rotate every 5000mi.

Alignment has been done twice. Once by dealer, once by Firestone. I bought their lifetime rotate, balance, road hazard, alignment when we first got the truck. $220.00, excellent investment, I think.

[SS396]

I run the same pressures as everyone else, but usually never lower them when empty.

Rotation is key though, in 13,000 miles my rear tires are worn twice as much as the front. Loss of rear wheel traction with all that power. :D

Although I rotated them, I want them to wear out so I can dump the 245's and add 265's

[Web]

I did some research on this and based on the my actual weight on each axle..I run empty at 55/45.

Loaded witht he 5'er the front axle has only 50lbs more than empty..so loaded I run 55/75.

Hope this helps

[roegs]

Same as Frank (and others) with 55 in front and 45 in the rear. I've noticed that if I run less than 55 in the front, it tends to bounce more than I care for.

[Lone Eagle]

How much do I need in my new BFG 265 ATs load range D? They are rated to carry the same load as the Firestone 245s but at 65 PSI. Later! Frank

[NWDmax]

Lone Eagle I run 60 psi front and back with my BFG's(285's).When I'm loaded pump the rears up to the 65 psi max.
Blake

[peachin]

Stock Tires - 55 front - 80 rear - when towing -

I am usually towing - so when unattached I sometimes leave the rears at 80 and sometimes down to 65 - 70.

12,500 miles on this new D/A 2500HD - Rotation front to back at 7,000 and will again at 14,000
no noticible wear - other than normal - no uneaven wear. The most destructive thing you can do is drive underinflated. I guess we learned this from Ford's experience with Firestone - both at fault - underinflation - causes heat - heat is very destructive to tires.

The above posts may provide comfort - but where is the authority to use a tire this way? I'm alway open to change to any discussion that has a proven reality.

[jbplock]

I believe it's safer to have a tire over inflated (but not exceeding it's max rating) than under-inflated (i.e. Firestone on Explorers). An under inflated tire will run hot causing pressure to increase thus increasing the potential for tread separation.

I can't remember where, but I read the following method of setting optimal tire pressure.
I've tried it and seems to work.

1. Inflate cold tires to the recommended or estimated nominal pressure.
2. Drive the vehicle and warm up the tires
3. Recheck pressure with the tires "hot"
4. If the pressure has increased by 10% then the cold pressure is correct and/or safe.
5. If the pressure increase is less than 10% reduce the COLD pressure value.
6. If the pressure increase is more than 10%, INCREASE the cold pressure. A greater than 10% increase indicates an under inflated tire.

This assumes that the tires have the correct load range for the weight of the vehicle and load.

I'm not a tire expert but this seems to make sense. Any comments? Can anyone confirm this method?

[Lone Eagle]

Bill, I used to be a tire expert and that doesn't make any sence. Summer to winter makes a big difference in the hot to cold ration. Even wear will determine the correct pressure. I can give you a short example. I went out late one afternoon to check my trailer tires before a trip. The two tires facing west were 4 PSI higher than the other two. I always check them now early in the morning now ;) . Later! Frank

[Inspector]

I ran a set of Michs for 65 thou towing a 36ft fiver. They were on a one ton duelly. The trailer road loaded was probably near 13+ thou.
I rotated every 5 thou.
The tire pressures I used for all that was 60 front and 55 in the rear duels. The tire wear was even for all six over the life of the tires.
I now have a 2003 with Goodyears and I am doing the same with those. I don't think I will get the same wear out of those but I will try.
The ride is very comfortable and they seem to stay cool.
Denny

[jbplock]

Frank,
Thanks for the feedback…. smile.gif You inspired me to dig into this a little deeper and I agree that setting tire pressure cold is key. I think its also safe to say that an under-inflated tire is not safe as it will generate excess heat due to increased rolling friction and side-wall flexing. The excess heat causes the pressure to rise higher than it normally would for a “properly” inflated tire. (See Car Talk) (http://cartalk.cars.com/Columns/Archive/2000/November/02.html). Everything I could find on tire safety said to regularly check and set cold tire pressure to the manufacturers recommendation. For the 2500HD with 245’s, this is 55psi front and 80psi rear (80 psi is the max rating of the tire). I think we all agree that the 80psi is higher than needed for running unloaded. The question is how to determine a lower but safe value? Here is an interesting quote from an article on Tires & Wheels (http://4crawler.cruiserpages.com/Diesel/Tires.shtml#ProperInflation) regarding how to determine tire pressure for optimal tread wear.

“One of the most accurate (and complicated) methods is to measure tread temperatures right after a high speed run. Even temps. across the tread indicate proper inflation. This is how race teams judge tire pressure in their vehicles. A less complicated version of this temperature-base technique is to select a cold tire pressure such that after ~15 minutes of high speed driving results in a pressure rise of 3psi or less. Increased temperature of the air in the tire is the cause of the temperature rise, and the 3psi value is about 10% of a typical tire inflation and represents about a 50

[rtquig]

I've been running 55 in front and rear empty, and while towing pump both up to 75. Wear seems good so far at 22k with original tires.

[Greg McCall]

Originally posted by Lone Eagle:
How much do I need in my new BFG 265 ATs load range D? They are rated to carry the same load as the Firestone 245s but at 65 PSI. Later! Frank I have new BFG 265 A/T KOs. I am testing air pressures now and Started with 60 psi in the rear and 55psi front. To my suprise Truck handling felt very "squirley". It was like I lost have my handling :mad: I had the same type and size tire on my lighter 98 Z-71 and they handled fine.

I have lowered the pressure to 55 rear and 52 front and it has made a big difference to the good. I will be taking a trip this weekend so time will tell.
For the record the tires produce a smoother ride.

[JEBar]

Have 45,000+ miles on original Wranglers ... early on played with tire pressure but didn't find any difference in ride ... 7 tire rotation every 5,000 miles and run max (door sticker) pressure in all tires ... just looking at them I'd estimate a minimum of 20,000 miles of service left in them (could easily be more) ... Jim

[luvthesmellofdiesel]

Interesting... I have the stock 245 Bridgestone donuts (the summer tread donuts), and I have been running close to 70psi on the front and 55psi on the back (unloaded, no trailer). They look properly inflated. Am I doing something wrong here?

I don't want a blowout, hence the reason I am running 70 in the front. The front of our trucks (unloaded) are heavier than the back, significantly heavier. It stands to reason one would want more air in the front than the back. Am I the only who does this? Is this wrong? When I run 55 in the front, the tires are drooped pretty good, too much in my opinion which will cause heat buildup which leads to blowouts.

Tim

[mobowhunter]

Firestones LR E, 245/75/16
Front 60, Rear 50.

Getting ready to jump to 265, 275 or 285's have done enough research yet though to make up my mind yet on size.