RDXguy

The sticker on the door of my 2019 RDX Tech says 33 lbs for all four tires. The dealership always inflates the tires to at least 37 lbs. What do you recommend?

ceb

The cold inflation for any car is a compromise between handling (more pressure), fuel economy (more pressure) and comfort (less pressure). For the RDX, the recommendation is towards comfort because that is what the average customer wants.

Cold inflation means sitting overnight. The dealership inflation (if you've driven recently) of 37 probably translates into 34 or thereabouts.

That said, 37 cold is probably what I would use unless the ride becomes too harsh. Play around with the numbers and see what you like. In no case should you ever exceed the psi on the tire and you shouldn't vary by about 20% or so.

Remember that a "good" tire loses about 1psi per month and each 10 degrees in temps will raise or lower the pressure by 1psi - that why people complain that their tire lights come on in cold weather. The TREAD Act requires that the car alert the driver when the pressure drops by 25%. Most systems will alert around 15%, so around 28psi. If the tires were filled to 33 when it was 80 degrees out in August, and it is currently 50 degrees in March, so there are 7 months and 30 degrees, so a drop of about 10 psi - probably one reason the dealer does 37psi.

My TSX's door jamb says 33psi and I regularly run 39psi.

romer

Yotrek

37 lbs, is for 20" tires, I believe..

ceb

Unless you have "special" tires that nobody else has, they will lose about one psi a month - but - you may not notice because the temps are probably increasing from when you last put air in.

If you check your tires infrequently, you'll get a warning on a really cold day. You air them up and if the temps go up, then that "cancels out" the loss of air over time.

ceb

Think of the number on the label as a "recommended starting point" to determine where you like it.

37psi (if the label says 33), will increase gas mileage, decrease tire wear, will make handling a bit sharper, but will decrease ride comfort.

Play around with the settings to see what suits you.

Wander

You're on the right track. 36 psi for the A-spec with 20" wheels, according to the Owner's Manual.

Which has nothing to do with all the other trims ( 33 psi ) but who has time to read labels?

Agree with fine-tuning to taste. More for crisp handling and better efficiency, less for maximum traction and increased ride comfort.

But NEVER under-inflate for high-speed highway travel. Under-inflation causes tire overheating, and overheating causes blowouts!

All "label" pressures are recommended "cold inflation pressure". If the tires are warm from driving, the pressure will be higher than when they are cold. So if you "top off" when the tires are warm from driving, set them 2-3 psi higher.

ceb

Most of us remember the Ford Explorer/Firestone saga. Most believe it was Ford putting crappy tires on the Explorer. Here is Paul Harvey with the rest of the story:

Each of the deaths and injuries had one common thread - the tires were significantly underinflated (at least 25% and most were at least 30% underinflated. Then, in each of the significant (death and injury) accidents, the cars ran off the roadway in a left hand sweeper turn and the left front tire went into the dirt. In many cases, the vehicles were driving too fast.

The only reason that the general population blamed Firestone was because that was the tire that was fitted to the Explorer (that didn't like low tire pressures). If Ford had fitted Goodyear (or Bridgestone, or Dunlop or Michelin or Linglong) then they would have been implicated.

The result of the investigation was the TREAD Act that brought us tire pressure sensors.

But - remember that the TPMS is a fail safe and does not replace periodic monitoring. Remember that tire wear accelerates quickly at 10% low.

Madd Dog

I use a proprietary blend of about 78% nitrogen in my tires. I find that with normal temperature fluctuations, I need to adjust the pressure levels about once a month.

Master47

I use the same blend in everyday breathing with unbelievable results...