I have a 12v air compressor that I keep in the truck. It works better than expected for inflating tires. I only use it occasionally, it cost $10 & I doubt it would last if used regularly. However, it works OK for emergencies.

I agree with you on the small compressor. I used one to inflate the tire I plugged and it worked great, it just took awhile!

I'm thinking, -that one can just push such a vehicle around in the (roomy enuff) garage regularly, -in order to move the tires around to a new position, -the same part not always sitting on the ground or floor. As at least a partial remedy to this matter In lieu of regularly enuff driving it around the neighborhood, -which would probably be better as to this matter. Better than just nothing!, -if perhaps not good enuff. [color:"black"] [/color] [color:"black"] [/color] [email]norad45[/email]

As I understand it the problem is not that the same part of the tire remains in contact with the floor; rather, it is that the entire tire needs to get "exercised" by being run at speed , thereby mixing up the chemicals in the rubber which act as preservatives. I doubt that shuttling it around the garage will do anything to help the tire, but at least that might motivate us to keep them inflated! <img src="/images/graemlins/wink.gif" alt="" />

I'm not familiar with the chemistry involved, but I'll concur with norad45. I have also read that tires need to actually be driven around regularly to re-distribute the chemical preservatives within the rubber. I'm assuming that the preservatives on the surfaces that are exposed to air and sunlight become exhausted and more preservatives need to be "squeezed" to the tire surface through driving.

That brings up another question in my mind. Are spare tires made any differently? Those tires often just sit in the trunk for years and years without ever being used. I personally have never seen anything in any of my vehicle manuals about replacing the spare tire after a certain number of years. Well, the manuals always suggest that you drive fairly slowly for a limited distance on the spare, probably mostly to save wear and tear on the drivetrain due to the smaller size of mini-spare, but I suppose that advice also minimizes the chances you'll have a problem with the rubber in an old spare tire, too.

There are two different problems with the tires of a vehicle that is standing for a long time. When the tire has contact to the ground it develops a flat spot. The tire is no longer round and will not run properly. This can be remedied by regular shuttling or even better setting the vehicle on blocks to lift the tires from the ground. This problem may be lesser one as it´s easier to detect (thumping that gets faster at higher speeds). It may still be able to destabilize the vehicle.
When the tire is not exercised some chemicals that preserve it and keep it soft evaporate from the outer layers. This makes the tire harder and more brittle. This is really dangerous as the tire looses a significant amount of grip. Most drivers fail to detect this properly (the majority of drivers isn´t even aware of it). The towed vehicle may fail to negotiate an easy turn especially on wet roads. The tire should be used regularly at speed and with some load for some time at operating temperature to prevent this.

Max, I've never seen a flat spot on a tire but then again my vehicles never sit for more than 2-3 months in one place without being used, so I'll defer to you on that one.

Arney, I'm not sure why spares last longer but I suspect that car/truck tires, including spares, have a different composition than trailer/RV tires. Add to that the fact that car spares are usually kept in the trunk out of the elements, especially direct sunlight.

That flat spot is usually the result of the hardening tire material. The tire just keeps the shape it had during storage. For some time the effect can be reversed. The tire makes a slight thumping sound that goes away after some driving. If it sits too long the shape stays and the tire must be replaced.
I´ve seen the flat spot once. The vehicle stood for about a year and the tires were not properly inflated. The flat spot was about 3" long and the tires kept it while we pushed the car around. I didn´t really believe it before.