Do "eco-friendly" tires really live up to their name? According to the independent tire retail giant TireRack, it depends on the tire.
Most "green" tires claim to increase fuel mileage, helping to decrease a consumer's carbon footprint. TireRack decided to see if the eco-rubber really helps improve a car's fuel economy. In a new test, TireRack fitted a 2009 Toyota Prius with six different types of tires, and put each type through a 550-mile drive, which consisted of highway, city, and rural road surfaces.
A baseline test - using run-of-the-mill Goodyear Assurance tires - returned an average fuel economy figure of 51.4 mpg. All but two tires - the Michelin HydrogEdge with Green X and the Goodyear Assurance ComforTread - improved upon that baseline figure. By far, the most efficient tire was Michelin's Energy Saver A/S, which helped boost fuel economy to 53.8 mpg -- a 4.74 percent improvement. TireRack estimates that, if driven 15,000 miles a year, these tires could help save $52.50 in annual fuel costs, and reduce CO2 emissions by nearly 420 lbs.
Of course, eco-friendly tires often incur extra cost, but the second-place tire, Bridgestone's Ecopia EP100, is only $1 extra per tire than the Prius' OEM rubber.
For all the details of TireRack's surprisingly comprehensive experiment, visit their report here.