Rim/Wheel Material Effect on Tire Pressure Variation

[RidingOnRailz]

Rim/Wheel Material Effect on Tire Pressure Variation


My current car, and the one I traded toward it, both have alloy wheels. My wife's has steel rims with plastic wheel covers.

After three years of driving cars with alloy wheels, compared to my wife's ride on steel rims, I noticed one thing: I have to adjust my cars' tire pressures about twice as often as her's.

Question: Does the material of the wheel or rim a tire is mounted to affect the tire's ambient temperature, and hence it's air pressure?


*Side Note* Admins: Please fix the tags feature on new threads!

I added "steel rims, alloy wheels, tire pressure", assuming each separated by commas equals a single tag.

It always says I "exceeded maximum number of tags by 1", whether I use a single word tag or a string of words!

Thank you!

[Stealthee]

I think the issue has to due with the material corroding. If you keep the bead nice and clean every time a tire gets changed the issue will not happen as much. I have aluminum wheels on my Lancer and I've only had to put air in one wheel twice all winter. That wheel was repaired at one point due to a crack in the bead area on the backside. The other 3 wheels have maintained proper pressure all through the temperature swings, but I thoroughly cleaned the bead areas before tires got mounted.

[RidingOnRailz]

Originally Posted by Stealthee

I think the issue has to due with the material
corroding. If you keep the bead nice and clean
every time a tire gets changed the issue will not
happen as much. I have aluminum wheels on my
Lancer and I've only had to put air in one wheel
twice all winter. That wheel was repaired at one
point due to a crack in the bead area on the backside.
The other 3 wheels have maintained proper pressure
all through the temperature swings, but I thoroughly
cleaned the bead areas before tires got mounted.

But if mine were a dirty beads issue wouldn't my pressures be all over the place(front left 27psi, rear right 30, etc)?

I keep my wife's and my pressures to within 1/10th psi of where they should be. When the temperatures drop, as they did last week going into this week, my wife's dropped only 1psi(all four tires), and mine fell 2-3psi(all 4).

Conversely, in summer, pressures on both our car's tires increase at about the same rate.

[CapriRacer]

A couple of thoughts:

Air or nitrogen (or any gas for that matter) is going to behave the same regardless of the material the container is made out of.

There is a difference in the expansion (or contraction) rate of steel vs aluminum, the aluminum alloy being larger. That means that when the temperature drops, the alloy wheels will shrink more, and - perhaps - there is more leakage. If this is true, then when the temperature goes back up, the alloy wheels will have less pressure.

It's also possible that the measuring device is reacting differently.