Use only the grade of motor oil designed for your vehicle's engine.

The motor oil required by most vehicles contains two grade numbers that refer to the low a... read full tip

Use only the grade of motor oil designed for your vehicle's engine.

The motor oil required by most vehicles contains two grade numbers that refer to the low and high temperatures at which the oil functions best. The first number, designated for low temperatures, is associated with a W-which stands for winter-while the second number is the high temperature designation.

Using a motor oil grade that's different from the manufacturer's recommended grade (for example, using 10W-30 instead of 5W-30), can reduce gas mileage by up to 2 percent.

If you start using the grade of motor oil designed for your vehicle, you could conserve more than 10 gallons of gasoline per year.

If 10 percent of licensed U.S. drivers began using the proper oil grade for their vehicle, 200 million gallons of fuel could be saved annually-enough to fill the gas tank of each of the 18 million registered vehicles in Texas.

Source:

FuelEconomy.gov