I was talking with my tire guy the other day and he told me that in this cold weather keep an eye on your tire pressure if you have aluminum wheels. Apparently the bead of the tire may not stick to the wheel causing a loss of air pressure which at highway speeds could cause problems and around town an inconvenient flat tire. This may or may not happen on your wheels but it is something you should keep your eye on. This is not a Prius issue but a problem with any car with aluminum wheels.
Uh, I think he's making it up as he goes along. The air IN the tire shrinks in cold weather, but the bead doesn't leak. At least, in over 30 years living in cold weather -I've- never seen a bead leak from the cold. Tire pressure has always dropped when it gets cold, and comes back up when it gets warm.
I was driving today on the freeway and I noticed a few cars with low tirepressure. One was a van and it was so low that he was running on the side wall. Our temps today were 18-21Degees. Running on low tire pressure will kill the tire along with the driver and passengers. Make it a point to walk around your car before you start out or at least when you arrive at your parking place. Only take a minute and if you do it once a week you will catch any issues before it happens. You guys in the warmer areas, are not exempt. Remember ---tires are not cheap...
Actually, I set my inflation pressure to 42f/40r and then reset the TPMS. The warning light will come on when the pressure drops just at or slightly below the Toyota recommended pressures on the door sticker.
Something I worry about with aluminium wheels and cold weather is salt on the roads. The alloy develops skin cancer surprisingly quickly.
Well I have heard that alloy wheels are more susceptible to air leak than steel rims but so far I haven't noticed any (our '05 pressures are still intact since I last pumped it for them back in Sept and my dad doesn't check the pressures regularly so i was very surprised to see the pressures haven't dropped)
Just reported what I was told by someone in the tire business as I thought it may be a safety issue. Having been driving for sixty years I can say that I never had any leakage from the cold just low pressure which come up after driving for awhile..
I think a more likely scenario is that someone loses pressure over several months time (normal) and then when there is a cold snap, the pressure drops even lower to the point where the tire comes off the bead. But the root cause of this is neglecting to check the pressure regularly (at least once a month) rather than the fact that the car has aluminum wheels.