3500 Tire Pressure & Wheel Questions

[Extreme1]

2 Questions:



1) Can someone please post the newer ('99 & up I think) tire pressure info for the 3500? It gives different pressures for different loads.



2) What is the difference in wheel offset between a '98 & a '99? Did the mounting change at all ?



Thanks!

 

[Archive]

Tire pressure recommended in the newer models with the 235 tires: 65psi front, 50psi rears.



Older models with 215 tires: light loads. . front 65psi, rear 40psi. Heavy load: front 70psi, rear 65psi.



I know of no change in the offset for the 98-99 years. The change did not come til the 3500s starting coming from the factory with the 235 tires as stock!



Hope this helps!

 

[drag racer]

Maximum tire pressures are always molded on the tire. The Michelins that came on mine are 80 psig maximum cold. If you want maximum fuel economy and maximum load carrying capacity of the tire, they must be run at the stated limit. Others choose to run at lower pressures because the ride in the dually tends to be rough at max. pressure (especially when the truck is unloaded), but for me, it's max. pressure all the time in all six tires.

 

[tlippy]

Wrong information above!!!

There is a correct tire pressure for a specific weight on every tire. The maximum tire pressure printed on the tire is not the optimum tire pressure to use under all conditions. The maximum tire pressure printed on the tire should ONLY be used if you are subjecting the tire to the maximum load. If you are interested in determining the CORRECT tire pressure to use you need to know a couple of things.

1. The actual weight EACH tire is subjected to.

2. The manufacturer's Maximum Weight (from the sidewall)

3. The manufacturer's Maximum Tire Pressure (from the sidewall)

The maximums are designed to keep a flat tire profile on the road and prevent rounding of the tire edge or center wearout and provide maximum braking ability. For less weigth than maximum you must deflate the tire accordingly.

For my Dodge, the following applys:

a. Front tires: Act Wgt = 4200#/2 = 2100#/tire

b. Rear tires: Act unloaded wgt = 2850#/2 = 1425#/tire

Formulae: ATP=Actual tire pressure

ATW=Actual tire weight:F=2100#,R=1425#(measured)

MTP=Max tire press=80PSI(from sidewall)

MTW=Max tire wgt=3042#(from sidewall)

ATP/ATW=MTP/MTW or ATP=ATW x MTP/MTW

For my truck this calculates to be 55PSI for the front tires and 38PSI for the rear tires unloaded.

I increase pressure when I tow. For my situation that equates to increasing the rear tire pressure to 47PSI.

 

[Gizmo 007]

Word of Warning

A word of warning about running tires at max pressure. If you live where the weather can get very hot during the day, you run a severe risk of a tire exploding. I live in southeast Texas and tried running max pressure on my previous truck. Had two tires explode and ripped the fender wells clean off the truck (One tire on each side. ON THE SAME TRIP RUNNING EMPTY) It made a big mess.



The local tire shop claims that the failures were both related to stress and heat on the tires. I quickly let some air out. I run at about 70 psi front and rear.

 

[Extreme1]

Allow me to clarify...

Thank you.



tlippy, where did you get that formula? Makes sense, never saw it.



I'm looking for a lower rather than higher pressure. My early '94 rides STIFF compared to the newer trucks. No overloads either. According to my door jamb sticker, 65 psi front, 60 psi rear. I had read a referance to what Rob had posted on another post but I wanted to see the numbers. (Thanks Rob!)



I went ahead and switched to 235-85-16 tires when I bought tires last. Now that will limit how low a pressure I can run. There is a slight amount of clearance between the rears now but when I removed the outers to run on the dyno at Goerends a few weeks ago, I could see that they must "kiss" when driving over bumps. No wear or anything, just clean spots.



Now back to the wheels. I prices a set of forged aluminum wheels (4) from the Dodge dealer, yes the Dodge wheels are forged. Very good price compared to the aftermarket. However, these must have the same offset as the early second generation wheels because the catalog states that a 215-85-16 tire is all that can be run on them. I'll probably switch back to that size on my next set of tires but I would like to know how much more offset the newer (2000?) wheels have and if, by chance the front spacer was made a little thicker as well.



Sorry so long.

 

[KCJackson]

Unloaded 3500 with 215 E-rated

After 5 years, I have settled on this for unloaded use: 72psi front, and 40psi for the 4 rears, with the standard-size 215/85R16E tires. I originally had the rears at 50, but they suffered overinflation wear patterns (center tread wore out), and the power-hhop and brake hop was awful. I found 65 to be too low up front because the sidewalls gave too much squish and I got some scrub and outside tread wear.