The United States consumed 367 million gallons of fuel per day in 2011 and the global consumption increased 0.7 percent and reached an all-time high of 88 million barrels a day in this same year. With this much consumption I don’t know why drivers are not trying to conserve more fuel by driving slower on the Interstate, trying to reduce wasteful idling by turning their car off at drive up windows at banks and fast food restaurants.

Other fuel conserving practices that people tend to ignore is driving closer to the speed limit. Almost every driver I encounter on the Interstate is traveling at least 10 to 15 mph over the speed limit and sometimes faster. When drivers travel at an excessive speed fuel consumption goes way up. If you decrease your speed from 80 to 50 mph fuel economy can have an average increase of 20 to 70 percent.

This was the idea behind the 55 mph speed limit in the 70’s, the government thought they could encourage drivers to save fuel by posting a lower speed limit; the problem was everyone ignored the speed limit and drove faster. Now that the posted speed limits are 65 on most Interstates drivers are ignoring this speed limit and going 80 mph. If you factor in all the inefficiencies of the internal combustion engine, increased drag from the air and unburned emissions (that you can actually smell when they pass you), the driver traveling at 80 mph is using 20 to 70 percent more fuel to maintain this speed.

A driver that normally would get 25 mpg traveling at 50 mph would get 20 mpg, driving at 80 mph with a 20 percent loss and a dismal 7.5 mpg with a 70 percent loss in efficiency. This would require about 55 gallons of fuel to make an average 400 mile trip driving at 80 mph. If the driver stayed at 50 mph on this same 400 mile trip, they would only use 20 gallons of fuel a savings of well over half the original gallons at the higher speed. This example is an extreme situation as not every driver may lose up to 70 percent in efficiency driving at 80 mph. It does show how much fuel can be wasted driving at excessive speeds.

It does seem strange though because as the price of fuel goes up, drivers appear to be driving faster wasting fuel and money and compounding the problem of high fuel prices. Fuel being a limited resource is only going to become more expensive over time. We are caught in a vicious circle, as drivers continue to abuse and waste this precious commodity making it more difficult to balance the supply and demand, fuel supplies will eventually dry up.