Fuel economy is, no doubt about it, the new black for the auto industry, both from OEM’s (Original Equipment Manufacturers) and from the aftermarket. On the leading edge of those automotive fashionistas catering to this exploding market, are a few who’ve been specializing in black for years. Namely, tire manufacturers like Bridgestone, Firestone, and BF Goodrich. The federal government has known for many years that the tire you use have a massive impact on fuel economy, perhaps more than any other single factor. The key to a tire’s impact on efficiency lay in what is known in the industry as “rolling resistance,” which is exactly what it sounds like. The more a tire resists rolling across the pavement, the more effort, and thus the more fuel, the engine has to exert to move the vehicle forward. From a fuel efficiency standpoint, the perfect tire would be paper-thin, have a tread surface as hard as steel so as not to catch in the minute cracks in the asphalt, would be very short to reduce rotating inertia, and always be perfectly round to ensure the least amount of contact with the road surface as possible.. If this sounds at all familiar, give yourself a cookie, since these exact wheels are used on the most fuel-efficient vehicles on the planet: trains. Trains have an average efficiency of over 450 times greater per pound than the average passenger car, due largely to their massive decrease in relative rolling resistance.

However, cars don’t run on rails, and don’t have the benefit of steel wheels to use as an excuse for taking a half a mile to stop. The price we pay for the flexibility we enjoy are those rubber donuts we call tires, which is why so many companies are pouring so many resources into improving them.

Believe the hype about “new tread designs” if you want to, but the primary means of making car tires more efficient is to make them more like train wheels. Harder rubber compounds ensure that they stay round and hard, reducing the road-to-tire contact patch and molecular adhesion. Economy tires are generally thinner than standard, and a bit shorter. This isn’t always true, since a taller tire can actually slightly reduce the speed the engine is turning in relation to vehicle speed (which is why you’re speedometer may be off five miles per hour after installing lower-profile tires.) This is a trick tire companies have been using for years to increase fuel economy on cars with more performance oriented gear ratios, but individual results may vary depending on application. Though it is true that there have been a great number of advances in tread and tire technology in recent years, one must consider before purchasing that these are all aimed at reducing the trade-offs of using train wheels on a car. Though it’s fair to expect some decrease in dry and cold weather safety, one would be hard-pressed to find a simpler way to boost fuel economy than simply changing tires.