The Future of Self-inflating Tires

Michelin is working with several other companies to develop an active pressure-management system called TIPM (Tire Intelligent Pressure Management), due to be available sometime in 2005. This system has a compressor that automatically adjusts the pressure in each tire while the vehicle is in operation to compensate for leaks and slow-leak punctures. The driver will be able to adjust the pressure depending on the desired driving mode: comfort, sporty, all-terrain or over-obstacle.

There are at least two other systems in the early development stages that are oriented toward the consumer market -- the EnTire system and the Cycloid AirPump system.

The EnTire Self-Inflating Tire system uses a valve that pulls in air from the atmosphere. It then pumps the air into the under-inflated tire using a peristaltic-pump action. The goal is to constantly maintain a specific pressure.

The AutoPump tire-inflator system by Cycloid has a small, wheel-hub-mounted pump that is powered by the turning of the wheels. When the system's monitor detects a drop in pressure of 2 to 3 psi, it pumps air into the underinflated tire. AutoPump has a warning system that is activated when there is a puncture.

For more information on self-inflating tires and related topics, check out the links below.

Self-Inflating Tires FAQ

How do self-inflating tires work?

Self-inflating tires feature valves that allow air to enter the tire and exit the tire as needed to achieve the right pressure, along with sensors that detect whether a tire needs more or less air.

Can a tire inflate on its own?

Tires can only inflate themselves if they're part of a tire-inflation system or self-inflating tire system. Otherwise, you'll have to manually inflate a tire.

Can I inflate tires at gas station?

Yes, most gas stations feature air pumps where you can quickly and easily add air to your tires.

What is the proper tire inflation?

Every tire is a bit different. You can find your vehicle's recommended tire inflation rating inside the driver's side door or in your vehicle's owner's manual. Most passenger cars are recommended to stay between 32 and 35 pounds per square inch (PSI).

Should you inflate tires to max PSI?

Stick to your vehicle's recommended tire PSI instead of the maximum possible. Over-inflated tires can be problematic (and even prone to bursting), so it's better to stay within the manufacturer's recommended range.

Sources

EnTire
Got Air? Wacky Weather Wages Tire Woes
Trends in Japan: Building a Better Bicycle
Lynch Hummer: Central Tire Inflation
Roadranger: Central Tire Inflation System Goodyear Investor Relations: 2001 Annual Report
Meritor Tire Inflation Systems (MTIS) by P.S.I
Dana Spicer Tire Management Systems
CM Automotive Systems: CTIS Specs
U.S. Department of Transportation: 49 CFR Part 571
CarandDriver.com: The Anti-Geneva Show
Heavy Duty Trucking: Air Apparent
LandLine: Tire monitoring and inflation systems
Gerald's Hummer Page: Central Tire Inflation System
The Groves: U.S. Army Trucks To Feature New Technology from Dana Corp.
Michelin Innovation in Tire Electronics
"Surface rutting of thin pavements and gravel roads under standard and reduced tire inflation pressures," by Ahmed Shalaby and Alan Reggin, Canadian Journal of Civil Engineering, 29, 679-691, 2002.
"Under (Controlled) Pressure," by Carol Ludorf, Transportation Communications, Fleet Equipment, August 2002.
"Air as Needed," by David Cullen, Fleet Owner, September 2003.
Integrated Publishing: Central Tire Inflation System
Forester.net: Breathing New Life Into Your Tires

How Self-inflating Tires Work