For those who keep driving, there are time-honored strategies such as buying cheaper gas and keeping tabs on a vehicle's fuel economy. But are those strategies more help than harm? Edmunds.com is out to debunk some long-standing myths about vehicle mileage - and what the company has come up with may change the way you think about gasoline and fuel economy: Your fuel economy gauge should be your guide. That's just not so, Edmunds says. "Our testing reveals that one such gauge claimed fuel economy 19% higher than the actual result," Edmunds says. "Calculating gas mileage manually is the most accurate way to monitor your car's fuel economy."
Cheap gas will wreck your car's engine. Again, this "fact" is right up there with the existence of the Easter Bunny and the ability of leprechauns to find gold. Edmunds performed a blind test on three samples of gasoline from major and independent gas stations and found no difference. "Because of the advances in engine technology, a car's onboard computer is able to adjust for the inevitable variations in fuel, so most drivers won't notice a drop-off in performance between different brands of fuel, from the most additive-rich gas sold by the major brands to the bare-bones stuff at your corner quickie mart," Edmunds reports. The firm does point out the value of fuel tank cleaning agents, which consumers may want to use twice a year. Using lower octane gas in a premium-recommended car will cause the engine to knock. Edmunds says that with the average cost of premium gasoline north of $4 per gallon, "drivers who are pumping premium are undoubtedly asking themselves if they can safely switch to regular grade, which is about 30 cents a gallon cheaper. In many cases, the answer is yes," Edmunds reports. The company says that with advancements in fuel technology, even regular gasoline is sufficient enough to avoid "knocking" from your vehicle's engine. Edmunds does say performance may suffer "slightly" from using regular gasoline over premium, with engine speed a half-second slower on the way from zero-to-60 miles per hour. But knocking won't be an issue.