A driving experiment. Does driving slower significantly change gas milage?
So I have read a few articles saying that driving slower can significantly increase the miles per gallon your car gets, thus saving you money. To test this theory I will try to drive slower for the next 31 days of May.
I usually fill the car’s gas tank up when it’s on empty so that I can minimize trips to the gas station. One tank of gas is 14 gallons and will get me about 360 miles. That works out to about 25.7 mpg (360 miles / 14 gallons).
Fuel mileage on the car is 21/29. I do about 75% of my driving on the freeway, and the rest on the streets. So I should get:
21 mpg * (.25) + 29 mpg * (.75) = 27 mpg
That’s an increase of only 1.3 mpg over what I get now. Not much, but I’ll take it if I can get it. The challenge will be to get the savings without losing patience.
The rules
I will not drive faster than 65 mph on the freeway. Frequent use of cruise control will be a requirement since 65 feels like you’re walking on California freeways. I will accelerate slower, and try to brake less. I think a good description I read once was to “pretend you have no brakes.” This will be tough in morning rush hour when tailgating is a must to keep other drivers from cutting you off.
The results
When I fill up I will take the miles driven divided by the gallons put into the car to get my gas mileage. So we will see if driving a little slower and less aggressively can actually make a significant change in the cost of gas. I encourage anyone else reading this to take up the challenge and drive a little slower for the next month, and post your results in the comments. It would be interesting to see if people driving different vehicles get different results.
