Your Mileage May Differ
An enthusiast's guide to saving fuel.
For enthusiasts, the gasoline that we put into our cars' fuel tanks is liquid entertainment. We enjoy driving and like to do it enthusiastically. But there's no reason we need be profligate with fuel. That is, there are plenty of things we can do to enhance fuel economy without diminishing the enthusiast value of our motoring.
Some of these are just plain common sense. Others are more subtle, but useful nonetheless. Some can be practiced all of the time; others are for when you're feeling especially fuel-frugal or just for the challenge of it all. Specialists at Ford, Honda and Toyota contributed many of these ideas; AAA also provided useful information. Along the way, I also learned what the EPA has in mind for fine-tuning its City/Hwy Mpg ratings.
The Obvious Stuff
Good vehicle maintenance is a given. Correct tire pressures, for instance, are crucial. According to Pirelli, a 3-psi deficit translates into a 2-percent hit in economy and 5 to 10 percent more tire wear as well. Modern radials are much better in this regard than bias-ply tires of old. Nevertheless, properly inflated tires are a win-win. They enhance handling and fuel economy.
A couple of words on mega-oversize fitments, though: Width detracts from vehicle aerodynamics, and it's not impossible that a styling statement can degrade handling, not enhance it.
What about tires with low rolling resistance? Are they worth a swap? In a word, no, especially for us enthusiasts. Generally, there's a trade of rolling resistance and ride/handling, and for once these latter two are on the same side of the equation.
Super-low-rolling resistance tires don't ride very well; nor do they grip very well. What's more (and a bit surprising), they don't wear all that well either.
As a telling point, Toyota originally fitted special low-rolling-resistance rubber to its early Prius hybrids. From 2004, though, largely in response to consumer feedback, the Prius rides on the same tires as its Corolla sibling.
One of my sources suggested that a rolling-resistance rating could be added to the Uniform Tire Quality Grading embossed on a tire's sidewall. Let consumers decide the inevitable tradeoffs among rolling resistance and the currently identified treadwear, traction and temperature. Maybe, he observes, there'd be a 2-percent reduction in fuel consumption with optimized rolling resistance. But remember you're likely to trade away grip, ride and wear.