Ok, we all know that we're supposed to follow our vehicle's placard for recommended tire pressure.

Fine. But there's an issue with tires in general that I believe NEEDS to be addressed but I've never seen any info about whatsoever.

To wit: My Lincoln Mark VIII says front & rear tires are to be 30 PSI. Easy enough.

But here's the issue:

This car came with Goodyears that had a MAXIMUM pressure rating of 35 psi.

The Firestone's I have on it now, same size and all, have a maximum pressure rating of 44 psi.

I don't know how many of you have actually 'felt up' various tires, but I have--and 44 psi rated tires have noticibly flimsy-er sidewalls than 35 psi rated tires...

Ergo---when I put 30 pounds of air in these Firestones, they look--and feel-- FLAT. And I AM wearing the outsides of the tires out faster than the middles, which of course is indicative of not enough air pressure!

I can find no info about adjusting "recommended" tire pressure based on the tires actual rating.

SO, if anyone HAS any info, I'm all ears!

In the meantime, I'm going to do an experiment with what's left of my tires...

My 30 psi rating is 86% of the factory tire's 35 psi max, but only 68% of the Firestone's 44 psi max. But 86% of 44 is 38 psi, and THAT'S what I'm going to start running in these tires. I'll bet the whole car feels better to drive, and they'll probably wear better. We'll see!

Any opinions on this?

Sounds reasonable to me.

You bring a good point and the different constructions and how that would impact the air pressure.

Sorry I can't help. But I must say, I've never "felt up" a tire before... you really had me laughing on that one.

I've always run my Firestones at 35-40 PSI but recently for fuel efficiency inflated them to the 44 max.

I honestly don't like them fully inflated as obviously the ride is harder and the steering on my wife's Trailblazer feels too light at speed.

I was told by the guy at Costco to follow the tire's recommended PSI on the sidewall for max performance. The door placard is for factory tires, replaced by the same brand/model. I've also read this on the RV board I frequent as well..

If you put the full 44 max pressure in at 'cold', you'll over inflate when they get warm increasing the hard ride quality. He said the best pressure is about 2-4 lbs less than tire placard at cold. He also recommended a digital tireguage for accuracy, and in hot weather, check every 2 weeks and reinflate as necessary for max MPG. Tires lose about a pound of pressure a month.

Our Jeep has an onboard tire pressure monitor. Not sure how accurate it is, but it tells me if they need air or not, so I CAN be accurate!

Tire pressure recommendations are always a compromise between ride comfort, fuel economy, traction, handling and noise.

Lower pressure generally gives you better ride and traction, but handling and fuel economy suffers.

Higher pressure gives you better economy and handling, but traction and comfort can suffer.

Noise can vary from tire to tire, depending on tread pattern and rubber composition.

Your Lincoln is probably weighted toward ride comfort - while sacrificing some handling and fuel economy. I'd say go ahead with the 38 PSI - but remember you will lose some wet traction and be prepared for it.

Think you have the right idea about raising the pressure.

+1 on starting at 38.

I agree with Nu2, door placard refers to factory setup. I think the tire wear is a HUGE indication that the tires need more air.

I run mine at the cold air recommendation on the door placard. 32psi on the Pilot, 35psi on the RAM. Now, the boat I keep at max cold, which is 50psi. Question, I have a single axle, and the tires look as if they need to be rotated looking at the wear pattern. Does anyone here rotate their trailer tires? They are wearing as in steps on the outside.

If they're standard bias ply it shouldn't hurt to rotate. On radials, I've been told not to change the rotation direction as it could lead to sidewall failure. Someone here with more knowledge may chime in differently tho...

Rotate radials front to back only. Keep them on the same side of the trailer.

Tires should be inflated to manufacturers recomendations, ignore the door placard if different tires than stock.

Have your tires inflated with nitrogen. They will not build up air pressure from temp changes.

So what do you do if the max tire pressure on OEM-supplied tire says 44 psi and the door placard says to inflate to 32?

Also, with TPM systems with individual pressure transducers, you won't be able to go above or below the factory recommendation much without tripping a light.

Seems like he is giving conflicting advice.

here's an old rally racers trick...use chalk to draw a line across the tread of the tire. Draw the line on each tire, then drive the vehicle. If the chalk line wears in unevenly in the center then you're overinflating that tire. If the edges wear first, then youre underinflating. Its best to err on the overinflated side-but this method should allow you to figure out the correct pressures for the combined unique attributes of your vehicle, the tyre design and how you actually drive the car