Need Tire Pressure Enginner

[radar doctor]

I have a 4x2 stock 03 truck with factory Michelin's Tires. . My question is . . With the truck weighing just under 7000 lbs Total... Around 4K lbs Front Axel and around 3 K lbs rear Axel. . What Tire Pressure Would be the best for maximum efficiency, and Safety??? Thanks..... Bill

 

[Wiredawg]

Here's what I use...

Bill:



To determine ideal air pressure for a given weight:



1. take each axle weight and divide by 2

2. Take the result of from step 1 and divide by the weight rating of the tire. This will give you a decimal number.

3. Multiply that decimal number with the max air preassure rating for the tire.



This will give you ideal air pressure for front and rears.



FYI: I tend to put more air in the fronts by about 10 psi than the formula suggests. I don't care for the cushy handling in the front.



Hop this helps,



Wiredawg

 

[radar doctor]

Thanks

Thanks WD. . You are very Kind... Happy Motoring from Kansas... .

 

[J&LRam]

Bill

I run 70 psi front and 80 psi rear while towing 12000 lb 5er. Empty I run 55 front and 40 rear and I usually get 65-70000 mi on tires... ..... JIM

 

[CFiore]

the tire pressure on the side is actually derived from a few factors and every vehicle manufacturer uses subjective criteria to determine the published recommended tire pressures. Formost on the manufacturers mind is..... Ride quality-giving the customer the ride they expect. they do it by lowering the pressure in the tires instead of revalving shocks and custom fitting spring packs. Secong is for maunufacturers is safety. The tire manufacturer and DOT maintain safety, so auto manufacturers dont bother with it much.



Fact- Every tire is tested at ten times its sidewall rating before DOT will pass it.

Fact- Safetywise, the tire should not be run at less that the sidewall rating. Problem is tire pressure increases with the amount of friction which depends on weight and road surface and ... It also varies with altitude and ambient temperature. A cold tire (dodge single rear wheel truck with diesel and auto and crew cab and 4x4 long bed) resting at 70lbs will be 78 lbs after a few minutes at highway speed. Thus the cold temp rating. If you run highway speeds often and want longer tire life run more than the sidewall recommendation. It will be a hard ride, but a safe ride with less friction and less tread seperating heat. If you want a softer ride, buy a lower lettered tire, D rating perhaps. or increase sidewall ratio, but dont lower pressure.



chris

 

[GCross]

Draw a chalk line across the tires, drive for a block or two. If the center wears off first the pressure is to high, if the edges wear first, to low. The line should dissapear equal all the way across. This method is only good when running empty. If you load the truck this won't work because each load would produce a different result. In this case use the tire manufacturers recomendations.

 

[JRG]

Occasional Limits

Fact- Every tire is tested at ten times its sidewall rating before DOT will pass it.

PLEASE EXPLAIN...



I don't think you mean that if a tire has a max psi of 50# and a max load rating of 3000# that DOT tests them to 500 psi / 30,000# respectively. Or do you?



JRG