Quick and Important Tire Size question

[seafish]

Run the toyos on the front and the Coopers on the rear, measure from the ground to middle of hub with coopers on, and adjust air pressure in the front until the measurements are the are the same front to rear. This is the best way to equalize the front to rear.

The front will be heavier due to the weight of the Cummins and will push down more on the tires and will look flatter than rear of the same pressure. I run 35 psi front and 20-25 psi rear to equalize them out. When I add a load, I air up the rear to compensate. This way there isn't much binding at all. Plus I've done different sizes front and rear already.

Just in case everyone ask why my air pressure is very low, the tires are large in size and has a large volume of air inside. The more air, the more lift. Also at 40 psi only 4-5" of the tread touches the ground instead of the actual 12. 5", so I lowered to get the entire width on the road.

Shawn

What size and load range tires are you running??

I ALREADY run only 47 psi in the Toyos to keep the wear going evenly across, and they are ALREADY pretty squishy on the sidewalls.
In fact, after I run this set out, I may well return to oem size, whick sucks both for highway rpm and looks, BUT it seems that they are much better suited for both the mpg's and the higher pressures that you can run keeping the truck feeling just right on the road. For awhile I ran my Toyos at 65 psi, and they ran and felt great, BUT they also (obviously) wore dwon the centers MUCH too quickly.
I hate to admit it, but there might well be a reason for Dodge speccing the tire size they did... . :-laf

 

[Regcabguy]

Tires have their own manufacturing specs and need to be run together. Similiar scenario would be wearing the same shoe type on either feet.



During my poverty struck teenage yrs,I only had money for two tires. The tire dealer warned me of handling problems with mismatched radials. Sure enough,he was right. My vehicle was all over the road. My parent's loaned me enough dinero to purchase an additional two.



If we ran a 8. 5" wide tire the 285's could be inflated higher for normal wear. My truck got it's best mpg with 285-70-17's. Despite the higher rpm's it did better. I couldn't imagine 265's unless you had the late issue 6. 7 G-56 with the 0. 74 final drive. I'd still like a 275-80-17 AT. With prices on the rise,maybe the tire company's will pump one out.

 

[SRay]

Seafish: I run Toyo M/T open country, 315/75/16, 10 ply rating, load range E. These tires are very stiff and strong, stronger than your A/T. They are able to help hold up the truck more due to the stiff sidewall. I had to lower them to prevent wearing out the center. Now have almost 70,000 kms on them.

Shawn

 

[seafish]

Tires have their own manufacturing specs and need to be run together. Similiar scenario would be wearing the same shoe type on either feet.

Dave, are you saying that I won't be able to walk a straight line if I wear a different style boot one each foot?? I'll bet I could!!!



That being said, I DO get your point... .



When I was a student I also could only afford a pair of used tires for my 1968 Plymouth. Obviously a common theme for students. The guy before me was running a full set of Bias Ply, and when I went to put the new pair on, I bought a pair of good condition, used radials. The tire guy told me that would be fine as long as I had the radials on the back (drive) tires and the bias on the front (might have been the other way around??) In any case, all was fine, until the day I forgot some books for class after I had already driven down the road a 1/4 mile or so. The house was at the end of the road, so I figuyred I would just back up (and practice high speed reverse maneuvers) but as soon as was going faster then 15 miles an hour, the bias ply versus radial tire effect came into play (since now the radials were on the "front" and the bias were on the "rear", and I was ALL OVER the road befeore I even knew what was happening. NOT sure what the moral of the story is, though certainly do NOT mix bias and radials is one of tehm. That being said, I thought that mixing radials was OK, though obviuosly NOT diffrent sizes on the same axle or diffrent sizes on 4wd trucks. Though obviously, if it CAN be avoided, it SHOULD be avoided. I'll definitely avoid it in this case, though still want to try the Coopers AT3 with their 55k mileage warranty.

 

[seafish]

Seafish: I run Toyo M/T open country, 315/75/16, 10 ply rating, load range E. These tires are very stiff and strong, stronger than your A/T. They are able to help hold up the truck more due to the stiff sidewall. I had to lower them to prevent wearing out the center. Now have almost 70,000 kms on them.



Shawn

Thanks for clarifying!! I was pretty darn sure that I didn't want to drop my tire pressure much lower then I already have them, even though Toyos psi chart for the AT takes em all the way down to 35 for the weight of my truck.

 

[seafish]

PS--If anybody want s even MORE info on Toyos and Infaltion, check this out--

http://www.toyotires.ca/sites/default/files/loadinflationtable.pdf

WARNING--it deals with ALL classes of tires, not just LT

 

[SRay]

Seafish: not a problem! I myself don't mind mismatched tires as they were free take offs with decent tread left.



I'm due for a new set of Toyo M/Ts next year. There's still tread left, for another 10,000-15,000 kms. Would've lasted more if I haven't laid rubber on pavement several times, and a tug of war with a 500 hp Duramax with tires smoking and peeling rubber on pavement as well. :-laf While he did beat my Dodge by a few feet, the Duramax lost almost 30,000 kms worth of rubber from his nearly new Toyo M/Ts while burning them at 130km/hr. :-laf My tires were only turning 40 kph.



For now I've got my Toyo G-02 winter tires on. THESE are aired up more,:-laf I think about 45psi front and 35psi rear.

 

[SRay]

Seafish: Yeah I'm pretty low on pressure according to the chart, but I did what would work good and has succeeded in making the tires last as long as it did.



I hated wearing out good expensive tires right in the center while the outside area still has lots to go.



I know just about everyone will tell me that's way too low, but no blow outs or etc. I do add air when I carry loads, etc.



Shawn

 

[seafish]

I hated wearing out good expensive tires right in the center while the outside area still has lots to go.



Shawn

Yeah, I did that to my Toyos for the first 10k mile before I realized what I was doing and others gave me better advice.

 

[SRay]

Do you like the Toyo A/T?



What advice did you get?

 

[seafish]

The Toyo AT 285/75/17 LRE tire is a an excellent tire,

I only wish that I could get more then 25k from a set of $1200 tires.

Regcabguy, and some others, DID point out that I had them WAY overinflated at the 65 psi I was running them at, thus leading to preamture treadwear down the centers. I aired them down to as low as 40 to compensate, and finally settled on 47 as a nice compromise for mpg, handling and wear.

 

[SRay]

Yeah, I've been told the A/Ts don't get the amount of mileage like the M/Ts do. My Bro inlaw has Toyo A/t and doesn't like how fast they wear.



He says my tires are Way better at everything and even the prices aren't that different.



I'm for sure buying another set. Hopefully I'll try not to spin the tires, etc on pavement.



Shawn