It's very common knowledge these days that underinflated tires can have a detrimental effect on fuel mileage. A motorist can easily lose 3 or 4 percent in gas mileage when tires are under-inflated, and probably more important is the fact that an improperly inflated tire compromises handling and braking. So be sure to check your tire pressures regularly. Another new movement in the tire industry is the introduction of fuel-efficient tires.
California and the federal government are currently pursuing regulations to rate replacement tires for "fuel efficiency" in an effort to influence consumer choice. In theory, if a tire is more fuel-efficient, less gas is burned and therefore less CO2 is emitted into the atmosphere.
The National Highway Traffic Safety Administration (NHTSA) is drafting a "consumer information system" to rate the fuel economy, safety and durability characteristics of most replacement tires. NHTSA has established test procedures to be used by tire manufacturers in determining tire ratings, but is still considering options on how to convey the information to consumers at the point of sale and on the Internet. Companies that only produce 15,000 units or less in a tire line (or 35,000 tires in total brand name production)--mostly tires for classic and antique vehicles or off-highway vehicles are exempt, since fuel efficiency for these types is not a primary consumer concern. Tire manufacturers are considering new rubber compounds, tire designs and other methods to boost efficiency without negatively impacting traction and strength.
The premise for the new program is to allow consumers to compare ratings for different replacement tires and determine the effect of tire choices on fuel economy, or the potential tradeoffs between tire fuel efficiency (rolling resistance), safety (wet traction), and durability (treadwear life). When it comes to consumer information, the big question is whether the focus of attention is misplaced. Will consumers be dissuaded from buying tires that may have improved performance, handling or appearance features, based solely on a rolling resistance rating? In addition, the program may easily distract consumers from focusing on more important safety issues such as tire inflation and overloading of vehicles.