Question about tire pressure and why OEM states that it needs to be set at 50 PSI

Although the technology has changed in recent years, the LOAD RANGE specification on a tire determines the designed operating and maximum pressure on each tire.

http://www.tirerack.com/tires/tiretech/techpage.jsp?techid=55

I hope the link works.

The MAXIMUM pressure of a tire should match the maximum pressure of the rim it is installed on and the suspension of the vehicle. 50 psi can split a rim that is rated at 45psi maximum. And I am speaking from first hand experience. When installing a tire the bead must seat and the man doing the installing should set the line pressure at the maximum pressure allowable on the tire/rim to push the bead out to its seat and then reduce the pressure to the recommended operating pressure.

Marketers wish to make buying tires a “Wizard of OZ” experience so the salesman can control the situation. You can assume that the “perfect” tire for your car is the one that is on the shelf with the highest markup or the one that pays a premium to the salesman.

With that being said I second Capri Racer in his statement. Understanding tires and their specifications are confusing to many. I probably have had similar conversations with many people over the years!

Correct me if I’m wrong, but the doorframe pressure is a recommended tire pressure. It is not a limitation, at least not in the way that GVWR is.

If the OP wants to run a different pressure…well, that makes him a “test pilot” of sorts w/r/t handling and whatnot…but as long as he’s within the tire pressure on the sidewall, he’s not busting a limitation.

I agree. Let me add, what is often omitted in many cars is whether the car/ truck is carrying a light, nominal load or a heavy load. According to Tire Rack, there is a difference and though there is pressure on the door jam, knowing that you may add more air as per owner’s manual for carrying heavier loads, is pretty important info. It’s important because often it’s the only way you can take full advantage of safely using the maximum GVWR as a guide.

I still suspect the wrong tires are on the truck. I also think running any tires at their maximum pressure is inviting disaster.

I’ve attached a chart that I think is excellent that cross references the information.

http://marktg.toyotires.com/file/loadinflationtable.pdf

I have not had any issues with the tires. I have been running them at 45 psi and have been getting even wear. The last set of tires were run at 45 as well and wore evenly.

Just an FYI:

Evenness of tire wear isn’t highly dependent on inflation pressure - things like alignment and driving styles can completely over-shadow the affect pressure has. So tire wear isn’t a reliable tool to tell if you have the pressure correct.

That is true. I havn’t had any problems with running 45 since 2004. What pressure would you run them? I feel that staying close to 50 psi as the door sticker suggests is my best bet.

Recently I found out a coworker has a similar pickup truck (a few years older) and is running the same tires on it. I am going to ask to see what his door sticker “recommends”. I can’t seem to find any other information that is more “legit” to sway me from keeping them close to or at 50 psi per the “sticker”.

The sticker pressures are develioped by the automaker’s engineers with the tire engineer to provide, 1) the best ride comfort, 2) the best load carrying capability, and 3) the best fuel economy. When all three line up with the max COLD pressure on the sidewall, is the optimum pressure. Criteria 1) wants low pressures, 2) and 3) want high pressures. If it is an SUV, 1) will take some precendence, for most 3/4 and 1 ton trucks, 2 and 3 prevail. 1/2 tonners are a compromise. That’s what you have here. Ride is compromised for the other 2. Use the sticker pressure because ALL of the performance, mileage and durability testing on the truck was done with those pressures. You don’t want to waste all that high powered engineering do you?