Blazer Forum - Chevy Blazer Forums - 15 Tips To Get Better Gas Mileage

1) Keep your engine tuned up. Bad spark plugs and incorrect spark timing can have a big effect on gas mileage.
2) Don't use your air conditioner (A/C) unless you really need it. The A/C compressor puts an extra strain on the engine.
3) Make sure your tires are properly inflated. Under inflated tires cause more resistance to travel.
4) Avoid stop and go traffic by taking alternative routes or less congested travel times.
5) Ask other people with the same type of car what kind of gas mileage they get, it may alert you to a problem with your car.
6) Use a good engine oil, preferably a synthetic or standard oil treated with a friction reducing oil additive. These have been known to improve fuel economy by as much as 12%.
7) Reduce the weight in your vehicle as much as possible. (Good excuse to get the mother-in-law out of the car)
8) Tailgating can AMAZINGLY improve your gas mileage, thats why race cars "bump-draft" in Nascar, BUT IT'S ILLEGAL AND DAGEROUS DON'T DO IT! (Bump-Drafting is when one race car bumps the rear bumper of another to reduce air resistance)
9) Keeping your highway speed at 60 mph can improve you gas mileage by as much as 25%, compared to 75 mph. (Not sure how but it works for me)
10) Avoid trying to increase speed while climbing a hill, your engine is already working hard trying to overcome gravity.
11) Keep your windows closed when possible. Open windows actually reduce gas mileage compared to using the A/C.
12) Remove accessories, such as luggage rack, etc. that lower the aerodynamics of your vehicle.
13) Aggressive driving (speeding, rapid acceleration and braking) wastes gas. It can lower your gas mileage by 33 percent at highway speeds and by 5 percent around town.
14) Avoid excessive idling, it can use a quarter to a half gallon of fuel per hour.
15) Using cruise control and over-drive gears can greatly improve gas mileage at speeds over 45mph.
A common misconception is that a dirty air filter can hurt gas mileage but on newer fuel injected cars it will only hurt acceleration. The vehicle's computer system senses a change in airflow to the engine and changes the flow of fuel to match.

My truck is a lifted 4 door Bravada with 31 inch tires and I am getting 17mgp city and 21mpg highway. I have tested this by running truck dry and then putting 5 gallons of gas in and drove until it ran dry again. I used my trip meter to count miles and then did the calculations. Sorry for this post being so long.