So I put a new set of Cooper Discover at3 tires on about 3,000 miles ago. I looked at them today and the fronts are still new at 16/32nds but the rears are already worn to 13/32nds maybe a little less. 

-I'm not out doing burnouts or even launching starts. 

-Little to no hauling or towing with these tires. 

-Pretty much all highway miles with maybe 20 miles of dirt road.

-60psi

It should be noted that my last set of tires (Firestone Transforce AT) wore quickly also, about 20k and they were down to 4/32nds. I just chalked it up as junk tires.

So what gives, I know they're softer tires but at this rate I'll be lucky to make it through the winter.

One theory I have is maybe my rear limited slip isn't releasing and dragging the inside tire through corners? The only reason I say this is a while back something in the back made a binding/clanking noise through tight corners while I was towing. It sure sounded like an LS issue. Couldn't replicate the noise the next day and every thing looked good when I pulled the cover. 

Any thoughts are appreciated cause tires ain't cheap!

 

I wasn't going to use those figures as an absolute, more like a suggestion, if that makes sense lol. My pressure is always going to be a bit on the low side (comparatively) due to the tires high load capacity rating of 3860 lbs at a relatively low pressure of 65 psi. 

Best off scaling still. I've seen some vehicles under weight my own and seen other tipping the GAWR...

Even at full GAWR of both axles using your tires.

5200 Front Axle GAWR = 43.7 PSI

6084 Rear Axle GAWR = 51.2 PSI

Total GVWR: 11,284 pounds... Way over GVWR of 8,800 pounds...

Edited December 11, 20159 yr by Mopar1973Man

That's the plan. 

Years ago I read an article in 4wheeler magazine about finding the perfect pressure for maximum tire life.

*The road surface must be paved/concrete and not gravel/dirt. 

*Using white chalk draw a line a couple inches wide across a tire.

*Drive about 100' and check the chalk line's wear pattern. 

*Adjust air pressure until chalk wears off evenly across the tire. 

Seems like it would be a pretty fool proof way of finding the correct pressure, albeit quite time consuming.

The math will get you right close to that same measurement too.

Just now, Mopar1973Man said:

The math will get you right close to that same measurement too.

Math? Do I look like some willie nillie mathamagician? Pfft, spending a few hours drawing chalk lines on tires sounds like the way to go. 

 

 

I ran 80 in my Michelins for around 15K. Other than riding just a tad rough there was no sign of tire life depreciation. Now I just Leave the front and rear at 60. Never know when something heavy is going in the bed.

44 minutes ago, TFaoro said:

I ran 80 in my Michelins for around 15K. Other than riding just a tad rough there was no sign of tire life depreciation. Now I just Leave the front and rear at 60. Never know when something heavy is going in the bed.

Look a this picture again TFaoro... I'm only 160 pound from GVWR. I have absolutely no need inflating to 80 PSI in the rear. I would be WAY over weight GVWR weights.

Even loaded like this I have no need for above 60 PSI.

Edited December 11, 20159 yr by Mopar1973Man

If you got out you wouldn't be so close to GWVR     JUST KIDDING!!

I see what you're saying, but my tires appear to be a bit softer. I was just saying that I have not seen ill effects of running them as high as they are. These tires have 30-40k on them and they're right around half tread  Not bad for pulling trailers in the summer (When the motor is in it) and some "playing" with a lot of power.

Ok TFaoro. Lets see if you right...

Take a tread depth gauge and measure from the shoulders and then from the center. Are all 3 numbers the same or is the center on just a wee-bit thinner? I'm going to bet the center is at least 1/32 thinner than the shoulders as a minimum. This is another way to judge your inflation pressure over inflated typically the center thin out quicker.

Or you can do like Hammer suggested smooth pavement and stick of chalk and see if the shoulders wear off.

Not really accurate though because I do a lot of turning in tight parking spaces, so it wears the edges a bit. I also rotate my tires every 3500-4K. I can measure though if I remember.

BTW I was expecting at least something about the weight comment  

Edited December 11, 20159 yr by TFaoro

GVWR is a fairly useless number on these trucks, why even really bring it up?

 

Michael, I would be shocked if you were not at a 6K RAW with that wood in the bed. You are certainly over 4500lbs which is what 60 psi can support.

Edited December 11, 20159 yr by AH64ID

Just approaching 79,000 miles on my Cooper Discoverer AT3's in stock size..............LT265/70 17E.

59 minutes ago, AH64ID said:

GVWR is a fairly useless number on these trucks, why even really bring it up?

 

Michael, I would be shocked if you were not at a 6K RAW with that wood in the bed. You are certainly over 4500lbs which is what 60 psi can support.

I wouldn't say it's useless. It's what the truck is actually made to handle with an appropriate factor of safety.

CAN it handle more? Of course! They have to build them stronger than they rate them, but I'd say staying around the gvwr isn't a bad idea. At that point get a trailer haha!

The worst underrating is the F450 though.... They had to keep it low to keep it low to "compare" it to the ram 3500.

13 minutes ago, TFaoro said:

I wouldn't say it's useless. It's what the truck is actually made to handle with an appropriate factor of safety.

CAN it handle more? Of course! They have to build them stronger than they rate them, but I'd say staying around the gvwr isn't a bad idea. At that point get a trailer haha!

The worst underrating is the F450 though.... They had to keep it low to keep it low to "compare" it to the ram 3500.

 

On some vehicles the GVWR is a fairly useful number, but on our trucks it is useless.

 

Don't exceed FAWR/RAWR and/or tires and call it good. Your frame is the same as a 3500 DRW so why should the GVWR stop you? I'd be willing to be the brakes are the same too, but I am not sure on 2nd gens.

I know on my truck I have the same frame/brakes/axles as a DRW and my only true limit is tires/wheels on the rear and I try to stay failry close to FAWR because I am  not sure what the limiting factor is.

GVWR is a marketing tool. A 2500 has to be rated lower than a 3500 SRW even thou they are 99.99% identical. There is no safety difference in the loading of the two, yet there is a difference in their ratings.

So yes, I truly feel the GVWR on a HD pickup is a useless number that isn't legally bearing in any factor.

 

13 minutes ago, AH64ID said:

 

On some vehicles the GVWR is a fairly useful number, but on our trucks it is useless.

 

Don't exceed FAWR/RAWR and/or tires and call it good. Your frame is the same as a 3500 DRW so why should the GVWR stop you? I'd be willing to be the brakes are the same too, but I am not sure on 2nd gens.

I know on my truck I have the same frame/brakes/axles as a DRW and my only true limit is tires/wheels on the rear and I try to stay failry close to FAWR because I am  not sure what the limiting factor is.

GVWR is a marketing tool. A 2500 has to be rated lower than a 3500 SRW even thou they are 99.99% identical. There is no safety difference in the loading of the two, yet there is a difference in their ratings.

So yes, I truly feel the GVWR on a HD pickup is a useless number that isn't legally bearing in any factor.

 

I was saying that in the assumption that there is a reason behind the numbers. You could be and are likely correct about the marketing scheme. Thank you for pointing that out

I know a lot of us exceed the number now and then. But I rather be aware of weights and what I'm hauling. Still in all the weight to tire formula should still hit close to the proper PSI numbers. Also you have to remember the 3500 series is with 6 tire vs. 4 tires on the 2500. Stability and safety is part of the GVWR number. 

2 hours ago, AH64ID said:

Michael, I would be shocked if you were not at a 6K RAW with that wood in the bed.

I'm not foolish. That is all very dry spruce. Looks impressive but not even heavy enough to sit on the overload springs. Now this load of red fir was much heavier. You can clearly see its sitting down on the overloads. This one I crept off the hill really slow. I know I was pushing my luck.

I always hated those loads that where just heavy enough to bang the overload springs on the stops. Listen to that weird clang noise all the way down a mountain.

Edited December 11, 20159 yr by Mopar1973Man

1 hour ago, dorkweed said:

Just approaching 79,000 miles on my Cooper Discoverer AT3's in stock size..............LT265/70 17En

1 hour ago, dorkweed said:

 

Which is why I think I have bigger issues than just tire pressure. 

I found this on the internet so it must be true.    http://auto.howstuffworks.com/auto-parts/towing/towing-capacity/vehicle/gvwr.htm

I'd rather to the side of safety than being willy nilly and be over weight.

Quoting from IBMobile link...

Quote

When you're towing a trailer, one last point to remember is that the entire weight of the trailer is not considered to be a part of your vehicle's GVW; however, the tongue weight -- the weight of the part of the trailer that actually attaches to your trailer hitch -- is part of your vehicle's GVW. Again, none of this changes your vehicle's GVWR. Trailers have their own specific gross vehicle weight ratings that, similar to the tow vehicle's GVWR should never be exceeded.

 

Quote

Safety is the driving force behind the GVWR for any vehicle. If a vehicle is overloaded, a number of problems can result. For example, if the vehicle is too heavy, the brakes may not be substantial enough to slow down or stop the vehicle effectively; the suspension components can become ineffective or possibly even break under the added strain and tires that are overloaded generate more heat, making them more likely to blow out. For safety's sake, the GVW should never surpass the GVWR.

 

1 hour ago, Buzzinhalfdozen said:

Which is why I think I have bigger issues than just tire pressure. 

 The only way I can see the rear tires wearing faster is the axle alignment is off. So it would be a matter of checking the axles for walking. Did you happen to break the centering pin in the springs? Possibly U bolt loose or rusted through? Kind of hard to see a rear axle moving unless there is some sort of damage.

Front axle is a different story being there is all the different axles you can apply to front tires on 2WD. As for 4WD trucks it more the typically ball joints, tie rods and/or track bar.

43 minutes ago, Mopar1973Man said:

I'd rather to the side of safety than being willy nilly and be over weight.

Quoting from IBMobile link...

 

 

 The only way I can see the rear tires wearing faster is the axle alignment is off. So it would be a matter of checking the axles for walking. Did you happen to break the centering pin in the springs? Possibly U bolt loose or rusted through? Kind of hard to see a rear axle moving unless there is some sort of damage.

Front axle is a different story being there is all the different axles you can apply to front tires on 2WD. As for 4WD trucks it more the typically ball joints, tie rods and/or track bar.

Good points and I'll go over everything again but I'll say it's doubtful. I put new springs hangers and U bolts in a year ago. Seems like the the more attention I give this rig the more it wants to fight back.