Friday 13 June 2008

Feature: How to achieve extreme fuel economy

Hypermiling... I've only heard about it for a couple of weeks now but before that, it was non-existent to me. Hypermiling is about driving carefully and efficiently as possible to gain the best fuel economy.

Jim Kelly plods along a back-country road, hugging the right side of the right lane. He constantly looks for traffic, both behind him and far ahead. "That red light's not likely to change in the next couple of minutes," he says, pointing to the traffic signal hanging over the road 500 yards or so ahead, "so there's no need to hurry.

"He builds up to 30 mph in his 2005 Toyota Prius hybrid, slows to 16 mph, accelerates to 28 mph, then slows back down again.

Mr. Kelly is using one of the techniques of "hypermiling," the fine art of wringing the greatest fuel economy possible from a vehicle through a selection of clever driving techniques. The 100-mpg barrier is the elusive goal.

It's All About Technique:

Hypermilers conserve fuel meticulously by driving at or below posted speed limits, minimizing use of brakes, keeping their vehicles well-maintained and their tires highly inflated. They also plan routes that pass through the fewest number of traffic signals and stop signs.

Those who are experts coast in Neutral whenever possible, and use sometimes-complex driving patterns to keep their engines at peak efficiency. To maximize fuel economy, attention to detail becomes an art form.

Serious hypermilers park their cars nose out at the highest points in parking lots so they can maximize coasting and avoid shifting from Reverse to Drive. They even plan their drives to avoid left turns, which could leave them stopped by oncoming traffic.

"I'm going to make a left turn up here, so I don't want to go too fast and waste kinetic energy," says Kelly, an EMS planner with the Chesterfield County Fire Department just outside Richmond, Virginia.

His technique of accelerating, slowing, accelerating and slowing again is called "pulse and glide" — accelerating to a point of high efficiency, then coasting for as long as feasible to gain maximum fuel-efficiency. Done right, it can achieve remarkable results.

Kelly's best "score" is more than 78 mpg in his Prius, which the EPA's newest test method rates at 48 mpg for city driving and 45 mpg on the highway. "Stoplights don't bother me so much, because as I learn my routes and know the lights, if I do it right I may never hit a red light," says Kelly.

Back on a major thoroughfare, Kelly gets stuck behind a slow-moving cargo truck and couldn't be happier. "This is great," he says. "Now I can go 20 mph on a 55-mph road." And without being the bad guy all the other drivers hate.

Happy in a Traffic Jam:

Scott Davis also hypermiles in a Prius, in which he achieved fuel economy of 78.2 mpg on a recent commute to his job as an information technology specialist. Davis, who lives in Glen Allen, Virginia, plotted his route on a topological map to see where he could make downhill gains and face the fewest climbs.

On an empty road, he says, "I'll go 20 mph in a 45-mph zone in the right-hand lane, and I'm the happiest guy out there.

" When a hulking SUV roars past him, Davis just says to himself, smugly, "This guy's burning more fuel than I will for the next 20 miles."

Many hypermilers drive hybrid cars such as the Prius, which combine an internal-combustion engine with an electric motor. Others milk mileage from conventional cars. Davis does both, sometimes using his Prius and sometimes his 2001 BMW 325i.

Hypermilers are an obsessively organized bunch. They keep detailed records, entering them in spreadsheets hosted on Web sites such as Clean MPG. They'll squeeze the most miles per gallon out of a tank of gas, record details of their driving — and then do it over again, trying to break their personal record.

200 MPG and Still Trying:

The acknowledged king of hypermiling is Wayne Gerdes, a former nuclear power plant operator who lives in the Chicago suburb of Wadsworth, Illinois, and who founded the Clean MPG Web site.

Gerdes has posted a lengthy treatise on the hows and whys of hypermiling, and attained more than 200 mpg in his Honda Insight hybrid over a 40-mile drive, and 127 mpg in a Prius on a 30-mile trip.

But he also recorded 66 mpg in his '05 Honda Accord and 85 mpg with his '03 Ford Ranger pickup. During his ownership of these vehicles, he has a lifetime average fuel economy of 48.6 mpg in the Accord and 38.5 mpg in the Ranger."

A top-rated hypermiler will shave about half off the gas bill of a non-hypermiler in the same vehicle," Gerdes says.

Many hypermilers use a $170 device called a ScanGauge that plugs into any car's OBD-II port and calculates instantaneous mpg, as well as mpg for trips and for full tanks of fuel. A device for the Toyota Prius called CAN-view provides even more detail and flashes the information onto the car's dashboard display screen. The immediate feedback adds a video-game aspect that many hypermilers find appealing — score a personal best, then go back and try to beat it.

Hanging Up To Drive:

Many hypermilers report that they have become better drivers. Attitude change is typical when one starts hypermiling, says Andrew McGuckin, one of the regulars on Clean MPG. "I actually notice probably twice as much out front as I used to," he says of his traffic-watching patterns.

"I'm not on the phone, eating, drinking, listening to music, or anything else," he says. "The personal relaxation was a surprise to me. This is time that I already have to spend every day, so why use it to work myself into a frenzy? On my 11-mile commute, I could arrive a minute sooner if I floored the gas all the way, but why?

"McGuckin has been hypermiling since January in his 11-year-old Honda Civic, which is rated at 33 mpg in the city, 38 on the highway. He averaged 57 mpg on his best-ever full-tank run. "That means I'm using only two-thirds as much gas, or saving $1 per gallon if gas is $3 at the pump.

"Debra Watkins is a hypermiler, too, though she doesn't know it. She's never heard the term before. But in her '05 Jaguar X-Type, or even her '83 Porsche 944 Turbo, she uses driving techniques straight out of a hypermiler's manual.

She stays off her brakes as much as possible, tries to time her driving to hit green lights, turns her car off while waiting in line at fast-food drive-throughs and at lengthy stoplights, accelerates slowly out of full stops and regularly uses the pulse-and-glide driving technique.

"It's something I've always done, that my dad taught me," says Watkins, who squeezes 30-plus mpg out of her Porsche, which has a combined rating of 20 mpg.

Via InsideLine > Hypermiling

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