Since I last filled up the gas tank I have driven 187.8 miles (302.2 km) and my average fuel economy has been 52.0 miles per gallon (16,8 km/liter or 4.5 liters/100 kilometers). I would estimate that I have driven 60% highway miles and 40% in the city since my last fill up, and the air conditioner has been on all the time.
This is in an almost totally stock, factory original, 5 speed manual transmission Toyota Corolla with a cruise control. The only things that are special about the car are that I have increased the tire inflation somewhat, and I have added a ScanGuageII which hooks up to the car’s diagnostic port and provides me with a read out of either the Average or the Current fuel economy. This gauge has allowed me to determine that this particular car gets its highest fuel economy when it is going about 35 miles per hour.
So what are the secrets to getting good fuel economy? You can look at this from two ways, the car and the driver.
THE CAR: To get decent fuel economy you need a light weight car with cruise control whose engine is no larger than 1.8 liters, has a standard transmission, has 15 inch tires, and is aerodynamic. Sixteen inch (or larger) and wider than standard tires greatly increase rolling resistance, and a rack on top of the car increases air resistance. Tire pressure should be kept no higher than the maximum indicated on the tire. Low tire pressure greatly increases rolling resistance. Living in the desert I personally have a strong preference for white cars, since they maximize reflectivity of the sun’s rays.
THE DRIVER: The biggest improvements come by learning how to drive in a way that maximizes fuel economy.
Accelerate very slowly, then maintain a slow and constant speed (using the cruise control any time it is safe to do so). Drive looking and planning far ahead, so that your use of the brakes is kept to an absolute minimum. When going down a hill or coasting to a turn or a stop, put the car in neutral (if you have an automatic transmission this may damage the car and is not recommended).
It really is not difficult, it just requires a different set of priorities. I find that many times when I am driving down the interstate highway with the cruise control set at 50 mph, I have a line of cars driving behind me. Not because they are upset and want to pass me, but because they also are tired of foolishly spending their money on rich Muslim Arab sheiks, and they know that driving slowly is the biggest key to getting better fuel economy.