It's all the rage in the tire world, and for good reason -- nitrogen inflation improves a car's handling, fuel efficiency and tire life. Nitrogen also allows for cooler running tire temperatures and improved fuel economy. These safety features make filling up with nitrogen a smarter choice for all types of drivers, including truck operators and average car owners. Proper tire pressure is vital to the livelihood of your tires. Underinflation can cause decreased gas mileage -- about 3.3 percent less miles per gallon. Nitrogen-filled wheels prevents air loss, therefore increasing the lifespan of your wheels. Because nitrogen increases fuel efficiency, it causes less damage to the environment.