I have the stock tires on my ram. I think the sidewalls say 40psi. Should I really run them that high? What is recommended? I want the most comfortable ride and best tire wear.

 

Dodge says to set the pressure on my stock tires/rims at 60/45 front/rear (light load) and 60/70 front/rear (max load).

 

When using stock tires, set it to what it says on the door jam. Depending on the year, it may have a tire pressure monitoring system, that if it isn't within the manufacturer's specs, the light will come on.

 

If your tire sidewall calls for 40-PSI max, then it sounds like your tire must be a D rated tire and not and E rated. The door air pressure guide is only good for E rated and not for a D rated tire as IIRC all ¾ trucks came with E rated tires. My self I keep my front at 65 PSI and the rear at 55 PSI when empty. If I have more then 55 PSI in the rear tires it bounces a lot and the rear end gets real squirrelly when empty. If I load weigh in the bed I go up to 70 for both front and rear as stated on the tire’s sidewall. If I’m towing a moderate to heavy weight trailer then I up the air pressure to 70 in the rear tires and I may or may not up the front to 70 PSI.

 

No its not a d-load its more than likely a standard load if its max pressure is 40psi. max pressure on a d-load range tire is 65psi. max load on a c-load is 50 psi. most standard load tires are 35-44 max psi.

 

YAMAHARIDER5,

You are correct as I went and looked at some tires I have in the shed and the LT 215/75/15 are load C are 50 PSI max and the other Michlien 245/75/16 off of a 2001 Dodge 1500 4x4 is 40 PSI max.

If cmharcou has a 40 PSI max tires on his 3/4 truck I would say he has the wrong tires on it and they need to be changed out for tire that is made to handle the weigh of his engine and a 3/4 ton truck with a load in the bed, behind it or both.

 

yeah he should definitly be running a e-load unless he gets into a bigger size like a 285/75-16 then he could use a d-load becuase the d-load in that size has a higher weight carrying cap then an e-lload in a smaller size. but yes he needs to step up for sure. just so you knw max load dual on most d-load 285's is 3007 pounds so single is around 3400 pounds i have 245/75-16s on my truck now and they are 2700 pounds dual and 3000 single. im putting 285's on this week in a d-load im getting nitto terra grapplers.

 

The one thing I don't like about D rated tires is that they have a weaker sidewall then an E tire. I've seen a lot of 3-ply sidewall D rated tires and hope they never do that with E rated tires. IMO when a person is hauling weight be it in the bed or on a trailer its best to have E rated tires with a good sidewall. Yes I know many haul a lot of weight with D tires but I don't like to take the chance of doing it and then get in a wreck just to have the insurance company not pay out 100% being I had an inferior D rated tire on the truck when it calls for E or better rated tires.

 

I run 70/70 in my 265 E's. Rides a little harsh but they were perfectly even.