I watched the Olympics in Beijing. One of the ads was of a car tire hitting debris in the road and "blowing out". But fear not! They were Bridgestone tires with "run flat" capabilities. An inner tube of air keeps the tire inflated enough to keep driving until you can get the tire fixed.
Some new cars do not carry a spare because the "run flat" feature eliminates the need for it. If your tire goes flat, just stop at a tire dealer and have them fix it.
Great idea, huh? Guess again!
Most "fun flat" tires can not be repaired because the internal air tube prevents getting to the inside of the tire to repair it. Sometimes (and I emphasized sometimes), a small nail hole can be "plugged" from the outside. The net of all this is, if your "run flat" tire blows, you probably have to buy a new one. There goes $250.
Next comes the availability factor. Run flat tires are not stock items. So if you need a run flat tire replaced, you have to wait. One day? One week? One month?
Then you need the same brand tire to match the three tires that didn't go flat. The dealer you stopped at may not have that brand and you are screwed. Yes, you can search dealers until you find the right tire.
So some people order an extra "run flat" tire so that it is available in case of failure. Oops! There goes another $250.
It is a bullsh-- system!
The lesson Grasshoppers is that for now, stay away from "run flat" tires. Some German designer in Europe came up with a better idea. He (or she) needs to get out in the real world.
Love,
Dad