Wait, Wait, Wait....
First, Dodge never listed the tire pressures on the door jamb for the 31
inch tires.
Second, The 35 PSI listed on the door jamb for the tires refers to the
standard wheel and tire package. It lists 35 PSI at all 4 corners.
Third, I have used the factory settings of 35PSI. This gave the following
results:
Front Tires: Significant wear on the outside of the tread.
Rear Tires: Significant wear in the center of the tire tread.
As an engineer you must agree that the more rubber you have in contact with
the pavement the better coefficient of friction. Thusly, better traction.
In the case of my rear tires, which were wearing in the center (Empty
Bed), must be caused by over-inflation. (You have to agree, because if
they were underinflated they would wear on the outside).
To remedy this, I used and Autocrossing trick. I got some white
shoepolish, and ran it across the rear tread. I drove around. I removed
some air pressure. I drove around. I did this until I had even wear across
the rear tires.
The fron tires were more of guess, as to what the right pressure would
be, based on the look of the rear tire which was now properly inflated for
the weight it was carrying. I think I settled on 38 or 39 psi for the
front. This took care of the cupping problem in the front.
I don't see how a tire that is not getting a proper footprint on the road
will ever wear properly.
>
>-I tend to disagree with this. 8" wheel is the preferred rim width for
>a 31X10.50R15. If they were too wide, the tires would normally wear
>quicker in the center than the edges, not vice versa, unless they were
>severely underinflated, like say maybe 10 psi under. I do not recommend
>changing the air pressure up or down too much from the factory
>specifications listed on the placard inside the driver's door jamb, but
>if you do, it is critical to maintain the split in air pressure that the
>factory has required. (re if it said 32 front and 34 rear, and you set
>the front at 28, then set the rear at 30) This differential is required
>to keep the truck in a straight line in panic-stop situations.
>Deviating from these numbers may cause loss of control and a tailspin.
> Just speaking from experience and a billion dollar companies 100
>years of testing and working with auto manufacturers. 8 ^ )
>Patrick
>Firestone, Baltimore
>
>ps- I never have problems with tire wear on my trucks. I average 50-60K
>per set, and all I do is maintain the proper pressure, rotate them every
>other oil change (every 6K miles or so) and check the alignment and
>balance every second or third rotation. I think the rotation in the
>most critical step out of all of these.
> The tires that get neglected for the first 25K miles are the ones that
>are cupped by the time they hit 30K.
>
>
>
>
This archive was generated by hypermail 2b29 : Fri Jun 20 2003 - 12:12:37 EDT