The most popular digital tire gauge in the world! The Slime Digital Tire Gauge measures from 5 to 150 psi and has a lighted tip that makes checking tire pressure at night fast and easy. You can improve your gas mileage by around 3.3% by keeping your tires inflated to the proper pressure. Under-inflated tires can lower gas mileage by 0.4% for every 1 psi drop in pressure of all four tires. Properly inflated tires are safer and last longer.