Optimum Speeds for Gasoline Efficiency

Lots of websites suggest you "drive the speed limit" to increase gas mileage. What the heck is this supposed to mean? I get the underlying premise that driving faster requires more fuel, but from state to state the maximum highway speed can go from 75 to 55 MPH. Why would anyone suggest you "drive the speed limit" when often times this is less efficient?

I would rather drive at a pre-determined speed that is right for my vehicle. So, has anyone determined the "most efficient" speeds for the Tacoma family of trucks? I personally have a basic 96 Tacoma 2WD, standard cab, 4 cyl. 2.4 engine. Any suggestions would be great.

Thanks for your time!

Slowing down to 45-50mph will be great for fuel mileage, but you will become a rolling road block to most drivers. To improve fuel mileage, inflate your tires a few lbs. over recommended pressure. Use the 5w-30 oil in the engine. Keep windows closed. Drive like you have an egg between your foot and the gas pedal. Anticipate your stops so you don't have to use but very little brake. Get the truck into top gear as quick as possible without lugging the engine. If you have air leave it off. Keep your wheels properly aligned. Remove any extra load you are hauling around, remove the spare tire and carry a can of tire seal. Keep your engine in good tune and change the air cleaner more frequently than suggested. Not much fun but these tricks will save a little fuel.

Clifton