Hypermiling can slash fuel consumption

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Before you decide to ease your pain at the pump by downsizing your vehicle or even by switching to public transportation, why not change your driving habits and boost your miles per gallon by 20 percent to 40 percent?

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That’s right — 20 percent to 40 percent! Others have done it and you can, too — but we’re not talking here about slowing from 85 mph to 75 mph on the highway. We’re talking serious changes — the changes made by “hypermilers” — drivers who have perfected the art of harnessing the power of every single drop of gas — to slash that $75 a week gas tab down to less than $50.

How do you do it? Installing an inexpensive miles-per-gallon display, increasing tire pressure and driving slower would make for a good start. Sure, you don’t like the sound of it — but wouldn’t it be music to your ears if that $4 gallon of gas felt like $2.69?

Saving gas by driving better

Wayne Gerdes runs the Web site Cleanmpg.com and is credited with coining the term “hypermiling.” He defines hypermiling as simply beating the Environmental Protection Agency, or EPA, combined mileage estimates on a vehicle from the time you drive it off the lot until the time you trade it in. Gerdes says he started trying to get more efficiency from his vehicles when the twin towers went down Sept. 11. He saw oil as not just a commodity but one that funneled funds back to regions that harbored anti-American sentiment. His practice of hypermiling grew, and in 2005, at the Prius Marathon, he drove a stock Toyota Prius 1,397 miles on a single tank of fuel — 110 miles per gallon. Gerdes, who averages 45 miles per gallon in his 2005 Honda Accord in everyday driving, says interest in hypermiling has spiked along with gas prices.

Fast facts
  • 1 less pound of tire pressure can lower fuel efficiency by 1.4 percent.
  • Shifting at 1,000 rpm less than usual can mean 5.5 percent better fuel efficiency.
  • Most cars operate most efficiently at 40 mph to 55 mph.
  • If your engine is going to idle for more than seven seconds, it’s better to turn it off.

“There are any number of reasons for hypermiling: global security, global warming, local smog, currency translations or trade deficits. Or, it could just be that you want more money in your pocket instead of giving it to the gas station,” says Gerdes. He recommends that drivers start by bringing tire pressure up to the maximum recommended on the sidewall, changing oil to a lightweight synthetic and installing a ScanGauge or similar fuel-consumption display for real-time feedback. The device displays real-time miles-per-gallon numbers and can instantly show drivers how their habits affect fuel consumption.

“People just don’t know when they step on the throttle or accelerator how bad it is. When they see it in real time, they can make slight adjustments to that. What we’re seeing is that just with that (and the increased tire pressure and proper setup), a 15 (percent) to 20 percent immediate increase in economy barely doing anything,” says Gerdes.

Philip Reed, consumer advice editor for Edmunds.com, says that some of the basic hypermiling recommendations can produce results. Reed has tried to increase the fuel efficiency of various vehicles himself and recalled a fuel economy test in which he was able to get 21 miles per gallon in a Toyota Tundra V-8, a vehicle that is only rated for 15 miles per gallon. Reed also recommends inflating tires to the maximum sidewall ratings. According to the Transportation Research Board, 1 psi, or pound per square inch, less in pressure in all four tires can lower fuel efficiency by 1.4 percent.

“It demonstrates that with different techniques, you can vastly improve the fuel efficiency of any vehicle that you drive. The question is how many of these techniques are practical for the everyday driver who is just trying to save a couple of bucks,” says Reed.

Advanced techniques

Some drivers, such as Gerdes, have turned hypermiling into a sport. The annual Hybrid Fest in Madison, Wis., promotes awareness and understanding of hybrids and alternative fuel vehicles. The event’s MPG Challenge puts various classes of vehicles on a 30-mile course where drivers try to max out the fuel efficiency of stock vehicles. In the 2007 event the winners included a Honda Insight (a hybrid) that scored 168 miles per gallon and a Ford Escape Hybrid that scored 60 miles per gallon. Drivers on the course can use just about any technique, but they do have minimum and maximum speed limits.

Hybrid Fest organizer Eric Powers says one of the most important gas-saving techniques is simply to slow down. Driving the speed limit, as opposed to driving five or 10 mph over it, can produce significant increased in efficiency. Powers drives a 2002 Honda Insight and has averaged more than 68 miles per gallon over the course of 111,000 miles. Keeping up the vehicle’s momentum by braking or stopping as infrequently as possible is also another way that hypermilers increase their efficiency.

“Anything you can do to keep your momentum going helps. Anything you can do to avoid starting from a dead stop,” says Powers.

Like Gerdes, Powers does not advocate running stop signs or taking corners at dangerous speeds, but misinformed critics have sometimes accused hypermilers of doing just that. Gerdes says that it simply means a driver maintains lower speeds and lets off the gas sooner when approaching a red light or stop sign. The whole idea is to conserve momentum and avoid having to punch the gas and engine speed by coasting as long as possible.

“When you hit the brakes, it is creating heat which is being displaced. Once you change your mindset and coast into lights and stop signs, not only is your fuel economy going to go up, but you’re actually becoming a more courteous and safe driver,” says Gerdes.

Hypermilers tend to drive a bit slower, and in a world where most interstates have a flow of traffic moving along at 80 mph, some argue that going 55 mph could be dangerous. Gerdes says he drives 55 miles per hour on 65-mile-per-hour highways and doesn’t see a problem. Sticking to the right hand lanes, he uses a technique called a “ridge ride” where he puts the right wheels of his vehicle against the fog line and rides near the edge of the lane. Gerdes says this position makes the vehicle stand out and drivers coming up from behind can see that he is moving slower.

“If people think that we are holding up traffic or it is impossible to do, it is not. I’ve driven in L.A., San Francisco, Salt Lake City, New York City, Chicago and Miami all in the past four months and I haven’t changed my driving habits,” says Gerdes.

Some can be dangerous

Other advanced techniques include “pulse and glide” — climbing to a given speed then coasting for a while then repeating the process. Using a technique called “auto stop,” the driver kills the engine and coasts until gravity and friction does the work to bring the vehicle to a stop. Some hypermilers have also engaged in ” drafting,” a technique where the vehicle rides directly behind a large vehicle, such as a semi-truck, to reduce the effects of drag.

Reed says drivers with manual transmission can glide in neutral on some highways, although it may be illegal in some states. Reed once conducted an experiment in his 2007 Honda Fit with “short shifting,” a practice where one puts the car into higher gears at a lower rpm. Driving a seven-mile loop and shifting at 3,000 rpm (instead of his normal habit of shifting at 4,000 rpm), he saw a 5.5 percent increase in fuel economy on his ScanGauge. Results can vary by vehicle but, in general, the lower a car’s engine speed, or rpm, the less fuel it will use. Short shifting is generally most effective in city driving at lower speeds and stop and go traffic where one might ride in a gear or two higher than in normal driving. The vehicle will have less power but will gain in economy .

“If you have a stick shift, you can pick up a huge amount (of fuel economy) by gliding and short shifting,” says Reed.

Other hypermiling techniques may be safe and legal but aren’t necessarily comfortable. Many hypermilers avoid air conditioning altogether or go through an almost scientific process of bumping up the fan as they shift into higher speeds. Gerdes recommends turning off the air conditioning while accelerating from a dead stop then turning it on once the vehicle gets moving.

When anticipating a stop of more than seven seconds, Gerdes says it’s best to turn off the engine. Whether it’s a long red light, the line at a fast food restaurant or waiting outside for children at the mall, Gerdes says killing the engine and rolling down the window can save gas. When a vehicle’s engine is running and it isn’t moving, the vehicle is getting zero miles per gallon.

“You wouldn’t necessarily turn your car off at every single light, but if it’s a three-minute light and it just turned red, shut that thing down. Hybrids do that automatically and you should, too,” says Gerdes.

Few drivers will ever be able to attain the efficiency some notable hypermilers get, but Gerdes says using a few of the tips can lead to a big savings. Increasing fuel efficiency by 20 percent would be the same as knocking bringing down that $4 gallon of gas to $3.20, and those who can double their fuel efficiency are cutting fuel costs in half. Gerdes says without making a single modification, the entire country could increase its fuel efficiency by 20 percent by simply driving better.

“I am paying (the equivalent of) less than $2 per gallon by the way I drive. If someone were to put up a sign with gas for $2, people would be lined up for a hundred miles. We have control of that through the way we drive,” says Gerdes.

15 more ways to slash fuel costs

1. Slow down: The U.S. Department of Energy says most vehicles get their best fuel economy at speeds between 40 and 55 miles per hour. Efficiency decreases rapidly at speeds over 60 miles per hour.

2. Blow up: Inflate your tires to the maximum pressure indicated on the tire’s sidewall.

3. Link your trips: Start with the destination that’s farthest away. Doing this assures that your car will be warmed up fully on the way to the first destination before you begin making a number of starts and stops.

4. No idling: Don’t let your car idle for long periods of time. Most engines only require seven seconds of gas to restart, so it’s more efficient to turn the vehicle off at long red lights, drive-throughs or other places where you might be waiting.

5. Tune up: Keep your car properly maintained by changing the oil and air filter, balancing your tires and aligning your wheels as directed by your owner’s manual.

6. Track miles per gallon: Calculate your gas mileage on a regular basis. The easiest way to do this is start with a full tank and reset your trip odometer. At your next fill-up, divide the number of miles driven by the number of gallons it took to refill the tank.

7. No junk in the trunk: The additional weight you carry in your vehicle doesn’t ride for free. It takes energy to move it around. Removing unnecessary stuff from your vehicle saves fuel.

8. Sack the racks: If you have a roof or bicycle rack and you don’t use it, remove it. They create aerodynamic drag, resulting in decreased fuel economy.

9. Go with the flow: Traveling at a constant speed on a highway in a flow of traffic is more aerodynamically efficient than going the same speed in isolation. A uniform flow of traffic generates a wind current you can benefit from.

10. Timely fill-ups: Plan to refuel your car during off-peak times to avoid lines and excessive idling.

11. Path of least resistance: On a super highway, choose the more open lanes and keep a cushion of air around you to avoid unnecessary and unpredictable braking/changes in speed. In a more urban setting, avoid bus lanes and lanes from which cars are turning into driveways and parking lots.

12. No sun, no moon: Keep the roofs closed at higher speeds. Some sunroof styles are better than others. The worst offenders are the kind which tilt and slide to the outside, on top of the roof. When open, these “roof-top spoilers” can significantly increase aerodynamic drag.

13. Drive shoeless: Some hardcore hypermilers drive in socks or bare feet so they can modulate the accelerator to the finest degree. It shouldn’t be that surprising. Race car drivers typically wear extremely thin-soled boots for similar reasons: for the highest level of tactile feedback from the vehicle, and to better finesse the pedals.

14. Avoid parallel parking: For on-street parking use pull-in, pull-out spots rather than spots that require multiple reverse and forward maneuvering. Pull-through spots are even better — they avoid burning gas to go in reverse.

15. Pick the periphery: Choosing a spot at the outside edges of a busy lot is far more efficient than driving around trying to get as close as possible to the building or destination.