There are many differing opinions as to whether your tires should be inflated to the max cold pressure, or even if you should over inflate them in order to increase gas mileage. Over inflation reduces the resistance of the tire traveling over the road. Less resistance means increased fuel economy. The question is, how much should you over inflate from the recommended inflation pressure?
One proponent of over inflation is Wayne Gerdes, who is a “hypermiler”. Hypermiling is a term refers to a set of techniques used to maximize fuel economy. Those who practice the techniques are referred to as “hypermilers.” The term was originally coined by Wayne, who is considered by the media to be one of the top hypermilers in the world. He is known to hold the record for gas mileage in some common vehicles, including 30 mpg in an Acura MDX and 59 MPG in a Honda Accord.
Many others inflate their tires to the maximum. In fact it is somewhat of a joke among the hybrid car crowd (and hypermilers) about how high they can get the pressure and improve their gas mileage. The trade off is you lose some of the tires adherence to the road (grip). Caution: This could make an accident more likely, particularly if you drive aggressively or operate a performance vehicle.
Remember though, over inflating your tires too much is going to cause them to wear out sooner. If you do have to replace your tires, consider energy saving replacements. Under federal fuel-economy standards, automakers equip new vehicles with tires that have a lower rolling resistance, which leads to higher fuel efficiency.
By requiring replacement tires to be as efficient as new car tires, gasoline savings would begin immediately. “Low rolling resistance tires” cost consumers only $5 to $12 more than conventional tires. But within a year, the average driver would recover the additional cost of the more efficient tires, and over the 50,000-mile life of the tires, the typical driver would see a return of $50 to $150.