And that's where "hypermiling" kicks into gear.
It's a term coined by Wayne Gerdes of CleanMPG.com, who says hypermiling can as much as double your mileage.
Gerdes and his team hold the world record - 2,250 miles in a single tank, which worked out to 164 miles per gallon.
Earlier this week, The Early Show reported on his drive from Chicago to New York in a hybrid Toyota Prius. He made the 800 mile trip in 17 hours - on 8.9 gallons, for an average of 71 mpg. His tank held 12 gallons, so he had a quarter of a tank left over!
We got such a huge viewer response to the story, we brought Wayne back Saturday to go over the techniques again.
Here they are, in detail:
Don't use quick accelerations, or brake heavily or frequently: They reduce fuel economy by as much as one-third at highway speeds and five percent around town. Environmental Protection Agency tests don't account for that kind of vigorous driving. Drive more slowly. Follow speed limits or go five m.p.h. below them. It will save you money. (And it's the law!) Higher speeds increase aerodynamic drag (wind resistance) and mechanical friction, which reduces fuel economy (FE). EPA tests account for aerodynamic drag up to highway speeds of 60 mph, but drivers frequently exceed that. Brake less: Slow down earlier, so you don't have to stop. Any miles per hour is better than zero, from which you then have to start moving again.
Don't idle excessively: It decreases average FE. The EPA city test includes idling, but drivers who experience more idling experience lower MPG.
Cold weather and frequent short trips reduce fuel economy: That's because your engine doesn't operate efficiently until it's warmed up. In colder weather, it takes longer for your engine to warm, and on short trips, your vehicle operates a smaller percentage of time at the desired temperature. And having your car idle to warm up doesn't help your fuel economy, it actually uses more fuel, and creates more pollution. Drive to your furthest destination, then, as you head home, stop at the closer destinations in order from furthest to closest, with the car warmed up for longer portions of your drive.
Remove cargo and cargo racks: Cargo and/or racks on top of your vehicle (cargo boxes, canoes, etc.) increase aerodynamic drag and lower FE. Vehicles aren't tested with additional cargo on the exterior. Remove the load in your car. Don't carry golf clubs all week. Don't carry books or exercise equipment. And it's not just in the car ...
Don't tow unless absolutely necessary: Towing a trailer or carrying excessive weight decreases fuel economy. Vehicles are assumed to carry 300 pounds of passengers and cargo in the EPA test cycles.
Minimize running mechanical and electrical accessories: Running mechanical and electrical accessories (such as the air conditioner) decreases fuel economy. Operating the air conditioner on "Maximum" can reduce MPG by roughly five to 25 percent, compared to not using it.
Avoid driving on hilly or mountainous terrain if possible: Driving hilly or mountainous terrain or on unpaved roads reduces fuel economy most of the time. The EPA tests assume vehicles operate over flat ground.
Don't use four-wheel drive if it's not needed: Four-wheel drive reduces fuel economy. Four-wheel drive vehicles are tested in two-wheel drive. Engaging all four wheels makes the engine work harder and increases crankcase losses.
Maintain your vehicle: A poorly-tuned engine burns more fuel, so fuel economy will suffer if it's not in tune. Improperly aligned or under-inflated tires can lower fuel economy, as can a dirty air filter or brake drag.
Try to purchase high BTU-content gasoline if available: Fuels vary in energy content, and some fuels contain less energy than others. Using oxygenated fuels or reformulated gasoline (RFG) can cause a small decrease (one-to-three percent) in fuel economy. In addition, the energy content of gasoline varies from season-to-season. Typical summer conventional gasoline contains about 1.7 percent more energy than typical winter conventional gasoline.
Inherent Variations in Vehicles: Small variations in the way vehicles are manufactured and assembled can cause MPG variations among vehicles of the same make and model. Usually, differences are small, but a few drivers will see a marked deviation from the EPA estimates.
Engine Break-In: New vehicles won't obtain their optimal fuel economy until the engine has "broken in." That may take three-to-five thousand miles.
Tire Pressure: This is a very important key to higher fuel economy. The higher the pressure, the lower the rolling resistance, the higher the fuel economy. The absolute minimum you should use is the driver's side door or owners manual recommended tire inflation criteria. That's what the EPA and your car manufacturer sets tire pressures to during the EPA city/highway testing. MAX sidewall is what Gerdes recommends for most, as it is well within the safety limits of your car and tire and it enables better FE than the pressure listed in the driver's side door.
Oil types and amounts are another important key to higher FE: We recommend a lightweight synthetic. You should double your oil change intervals. If you change every 5,000 miles now, you can do it every 10,000 miles. Use oil with a viscosity that is within the band of your automobiles lubrication requirements. That being said, not all oils are the same. If your automobile allows a 5W-20, you should be OK using a high quality Synthetic 0W-20. Mobil1 0W-20 has the lowest kinematic viscosity as well as superior wear and breakdown properties compated to ANY non-synthetic I know of. I recommend that, instead of filling the case up to the high level mark, you use just enough oil to bring the level up to between the high and low marks. You lose capacity in case of a leak and have a very slight increase in oil temps, but gain a slight amount of FE.
Install a fuel consumption display, such as a scan gauge: They can go on any 1996 or newer vehicle. It provides fuel economy feedback so you always know how you're driving. They cost $150-$170 dollars. They could save you 10-15 percent of your fuel consumption.
Even the way you park matters!: Never pull into a parking spot where you're nose-to-nose with another car, because that means you have to back out of it. You want to pull out directly. Always park on the highest point. Let the hill you are climbing slow you down, and you can coast down it.