M38A1CDN2 Tires

[Hanno Spoelstra]

Originally Posted by Retsarge

The old ones on my jeep were 17 years old, and yes I listened to the Jay Leno story.

What is the Jay Leno story?

[Paul Singleton]

Originally Posted by Hanno Spoelstra

What is the Jay Leno story?

https://www.hagerty.com/media/opinio...bb61d82ae20c6f

[rob love]

45 is the maximum, and that would be around the pressure you might have to go to to seat the beads when you install them. But the 28 psi is the reccomended pressure for the M38A1, based on the gross weight. As Grant has mentioned, it will have to do with temperatures, but is also based on the amount of sidewall deflection (which is related of course). It also lets you get the most mileage out of the tread, although in your case it will be more likely that you will exceed the expiry date of the rubber before you wear out the treads on your truck.



Note that 28 psi is the maximum, so would be the jeep with a full tank, crew and payload to max weight. You could go a little lower for better traction, but really, like most of us I'll guess you are just cruising maybe a couple hundred miles a year during the spring/summer.



If you were to drive them around with 45 psi, I think it will be like driving with Fred Flinstone wooden wheels. The pneumatic tires add some (if not most) of the smoothness to the Jeep's ride.



I just set my tire pressures yesterday, all to 28 psi. It allows me to engage and disengage the 4 wheel drive without driveline binding.

[Grant Bowker]

Originally Posted by rob love

I just set my tire pressures yesterday, all to 28 psi. It allows me to engage and disengage the 4 wheel drive without driveline binding.

This suggests similar rolling radius for both axles as a result of similar axle loads - or at least not horribly different. (so similar safety margins at both ends)

[rob love]

One would think it would, but there is a fairly significant difference between the front and rear axles when the vehicle is loaded. But really, aside from the driver, the passenger, and perhaps a radio set in the back, what kind of weight do we really carry in our jeeps?

[Hanno Spoelstra]

Originally Posted by Paul Singleton

https://www.hagerty.com/media/opinio...bb61d82ae20c6f

“Jay Leno needs about 1200 tires”

[Retsarge]

Thanks for all of the feedback received. The tire dealer insisted that l should go by the psi listed on the tire, I did not agree with him. The tires are now set at 28 psi. Shows how much some of these people selling and installing tires really know.
I wonder what psi Jay Leno had put in his 1200 tires??

Richard Mix

[Grant Bowker]

I think the tire dealer was doing "cover your ass" - tires at maximum pressure rarely fail, underinflated tires have significant failures...

[rob love]

45 is too high, 10 would be toooo low. 28 is just right.

I cannot imagine driving an M38a1 with 45 psi. Give it a try and you'll see what I mean.

I have also noticed tires cracking prematurely when they are at max pressure. Especially the STA brand.

[Retsarge]

Hi,
I pulled out the old tires paperwork. I bought the old tires back in April 2006, and they cost $95 ea and the tubes were free. During those 17 years l put about 9000 miles on them. I had no problems or flats during their life on the jeep.
What is the average life span for some of the other jeep tires that you guys have?

Richard Mix Jr.