kaydeejay wrote: The pressure marked on the tire is the MAXIMUM pressure at max rated load.
The pressure marked on the tire is actually the MINIMUM pressure needed to carry the max load.
How do you figure?
Its actually pretty simple. If the max load is 3500lbs at 80PSI,then 80 PSI is the MINIMUM pressure needed to carry the load.
Think about it,is the tire gonna carry the max load at 70PSI? How about 75PSI? The tire cannot carry the max load UNTIL you put 80psi in the tire. That means 80psi is the minimum needed to carry the max load.
I understand what you are saying now but you couldn't have worded it more confusing.The maximum pressure is not the minimum anything. It is the max pressure the tire is rated to be filled at, and not exceeded, to carry the max load rating.
Someone recently wrote, "The 2005 Nissan Pathfinder comes with 245/75SR16 with 2274 lb capacity at 44spi so the LT265/75R16D's have a capacity of 3,042 lbs @65psi . You need to get your story straight."
The problem is that I don't have a story -- I don't know enough to have my own story. The car came with BFG Long Trails, which were 265/70s. I just put on BFG AT's, 265/75's. The sticker that came with the car, a 2005 Nissan Pathfinder SE, lists both of those sizes, and lists them both at 35 psi. And that is what Costco used to inflate the new tires. I have since learned that this is wrong, according to BFG. And BFG says that I should inflate them to 50 all the time.
Again, you'd think the tire and automotive industries would have this absolutely squared away by now. There is a lot riding on it, so to speak, especially in the wake of the rollover and blowout scandals. We should not have to speculate and hunt for this info. I understand that the government can't babysit the situation, but the business folks have an incentive to do it right.
* This post was
edited 05/21/08 05:01pm by profdant139 *
profdant139 wrote: Someone recently wrote, "The 2005 Nissan Pathfinder comes with 245/75SR16 with 2274 lb capacity at 44spi so the LT265/75R16D's have a capacity of 3,042 lbs @65psi . You need to get your story straight."
The problem is that I don't have a story -- I don't know enough to have my own story. The car came with BFG Long Trails, which were 265/70s. I just put on BFG AT's, 265/75's. The sticker that came with the car, a 2005 Nissan Pathfinder SE, lists both of those sizes, and lists them both at 35 psi. And that is what Costco used to inflate the new tires. I have since learned that this is wrong, according to BFG. And BFG says that I should inflate them to 50 all the time.
Again, you'd think the tire and automotive industries would have this absolutely squared away by now. There is a lot riding on it, so to speak, especially in the wake of the rollover and blowout scandals. We should not have to speculate and hunt for this info. I understand that the government can't babysit the situation, but the business folks have an incentive to do it right.
So the
Costco is right to put only 35psi in the larger 265/75 tires since the smaller 265/70's were rated at 2403 lbs @35psi. BFG is just playing it safe by saying you should put 50psi in them but that is way more than you need in the front tires and the rears when not towing.
profdant139 wrote: I just put BFGoodrich All Terrain tires on my 2005 Nissan Pathfinder. The tires say they can be inflated to 65 PSI when fully loaded, but the door sticker on the SUV says 35 psi. And my local car mechanic (who is very knowledgeable) says to inflate the tires to 50 psi with a full load while towing.
Which one of these numbers should I believe? Thanks in advance for your advice.
I have the same tires and the door sticker on my Dodge states 35psi front and rear. I run them there normally but pump them up to 50psi when towing and loading the vehicle. While camping I leave them at that pressure but the ride is a little rough when unloaded.
I assume that the harm in running at 50 psi when not towing is that there will be too much wear in the center of the tire? I also know that running with too much pressure will be less comfortable. And I would guess that in wet conditions, too much air will reduce the footprint, which is not a good thing.
profdant139 wrote: I assume that the harm in running at 50 psi when not towing is that there will be too much wear in the center of the tire? I also know that running with too much pressure will be less comfortable. And I would guess that in wet conditions, too much air will reduce the footprint, which is not a good thing.
I have noticed less traction on wet surfaces when aired up to 50psi and unloaded. I still say 35psi unloaded (door sticker), 50psi loaded. Never had any issues with my BFG ATs over many miles. Sad thing is when you ask a question here you will get many uninformed opinions mixed in with the good advise. I drive my truck hard, corner hard, average interstate speed at 70-75MPH over 126,000 miles. Never had a blowout, just pay attention and do proper maintenance. Maybe it's because my tread wears out before the tires have a chance to dry rot.
kaydeejay wrote: The pressure marked on the tire is the MAXIMUM pressure at max rated load.
The pressure marked on the tire is actually the MINIMUM pressure needed to carry the max load.
How do you figure?
Its actually pretty simple. If the max load is 3500lbs at 80PSI,then 80 PSI is the MINIMUM pressure needed to carry the load.
Think about it,is the tire gonna carry the max load at 70PSI? How about 75PSI? The tire cannot carry the max load UNTIL you put 80psi
the tire. That means 80psi is the minimum needed to carry the max load.
What you are saying is true but it is not what is intended by the manufacter of the tire. Thay are saying that the maximum pressure for the tire is 80 PSI and it will carry "X" amount of pounds at that pressure.
There is absolutely no need to run these tires at max pressure on that Pathfinder. From the numbers he mentioned, it's fairly obvious he went from P to LT tires. I seriously doubt the wheels are rated to 65 PSI on his Pathfinder.
Yikes, Dawg! I never realized that the wheels had to be beefy enough to handle the pressure, but it makes sense. I have also heard that valve stems have to be sufficient to handle high psi. My guess is that if I don't go over 50 psi, I should be ok. Plus I tend to drive really easy when towing -- my speed hovers around 60, no sudden moves, my poor wife is dying of boredom . . . .
Wheels are irrelevant unless they are steel split rim, which the Xterra does not have. The weak link is valve stems. I went through this when I bought my LT's. Let me put it this way. What do you think will let go first, the forged or cast aluminum or the rubber tire or valve stem. Wheels have weight rating stamped on them but I have yet to see one with a psi rating. I have had mine to 75psi testing performance and there was no explosion.
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