One very cool automotive technology that will save gas is tire pressure monitoring, which will be a requirement on all 2009 vehicles sold in the U.S. A significant percentage of vehicles operate with under-inflated tires that not only rob fuel economy but also represent a safety hazard.
Here’s how the better systems work, a self powered sensor and radio transmitter, like the one pictured below, is installed in each tire. The range on these things is pretty short, no more than a couple of feet, so a receiver is installed in each wheel well of the vehicle. The on board computer processes the signals, measuring tire pressure and temperature (warm tires increase tire pressure by about 5 PSI), alerting the driver when pressure drops below a configured threshold.
Some systems are employing a passive technology utilizing magnetic coupling, which removes the possibility of battery failure from the equation. Lastly, there are some unreliable systems that simply measure wheel speed, calculating tire diameter and triangulating on a pressure reading.
This is just one more example of a technology solution available today that can increase fleet fuel economy.