Robin Quinn's driving instructor would be proud.
Nearly four decades after Quinn started driving, she has abandoned some bad habits - the lead foot, for example.
Instead, she has joined a growing number of enthusiasts who practice something called "hypermiling." They strive to maximize the number of miles they get per gallon of gasoline by, say, driving at or below the speed limit and braking as little as possible.
Many trade tips and boast about their high gas mileage on online forums that are growing more popular as gas prices rise.
The average price for self-serve gas in Maryland topped $4 per gallon yesterday, according to AAA Mid-Atlantic.
Thanks to hypermiling, Quinn, a Randallstown resident, calculates that she is getting nearly 27 mpg in her 2003 Nissan Altima, compared with 24 mpg previously. That can save her more than $100 a year.
"I was just surprised at how effective this little change of driving habits was," she said. "I've only done it two weeks and I'm thrilled."
Estimates of potential savings vary, but one expert says the driver of a nonhybrid vehicle could improve his fuel economy 50 percent by applying basic tips.
Wayne Gerdes, who operates the Web site cleanmpg.com and teaches hypermiling clinics at his home in the Chicago suburbs, said he began developing his techniques after the World Trade Center attacks - he was concerned about the nation's dependence on foreign oil - and true hypermilers are always striving to improve their gas mileage.
Other hypermilers stress the environmental benefits.
But some auto experts question the safety of advanced hypermiling techniques such as "drafting" - closely following tractor-trailers to cut down on the flow of air against a vehicle.
Leon James, a University of Hawaii professor who has written about the psychology of driving, said hypermiling can become a form of aggressive driving if, for example, drivers practice it in the fast lane, forcing others to drive around them, or if they coast through stop signs.
"If you were behind someone who's practicing certain features of hypermiling, you get very annoyed," James said. "Hypermiling can be a selfish thing to do."
Ed Kriston of AAA said that the automobile group encourages gentle driving to save gas but discourages aggressive types of hypermiling.
"Some of the things they do are very dangerous," he said. He pointed to drivers going below the speed limit on highways such as Interstate 795, where the limit is typically higher than those posted on most highways.
Critics have also said that drafting is unsafe, and in fact cleanmpg.com's Web site includes a disclaimer stating that it does not endorse the practice.
Gerdes said critics don't understand hypermiling. He urges motorists to stay to the right both to yield to faster drivers - or "rabbits" - that dart ahead, and to take advantage of the low-pressure systems created by larger vehicles passing them.
He said that he also has been on the receiving end of rude gestures from other motorists.
"I can tell you that the dangerous people are going 10 miles over the speed limit," he said. "I'd much rather be with a hypermiler than one of those."
It is unclear how many people are hypermiling. But high gasoline prices are inevitably going to lead some to change their driving habits, said Jake Fisher, a senior automotive engineer with Consumer Reports who has blogged about hypermiling.
Consumer Reports recently conducted tests on hypermiling techniques and determined that some are effective at reducing gas consumption.
The biggest factor in getting better gas mileage is driving at a moderate speed - 55 mph instead of 65 or 75 mph - the publication reported.
When the Toyota Camry's cruising speed was increased from 55 to 65 mph, the car's fuel economy dropped from 40 mpg to 35, it reported.
Other techniques include keeping tires properly inflated and avoiding frequent bursts of acceleration, sudden braking, the use of premium fuel and driving on a cold engine.
Kriston of AAA said hypermiling can undoubtedly be effective at cutting gas use.
"Doing those things, where you're trying to maintain a cruise as much as you can - it does make a difference, it really does," he said.
Hypermilers also use their air conditioning more efficiently, Gerdes said.
He cools his car before he starts the engine by opening windows and doors. Gerdes cycles the air conditioner on and off and recirculates the dehumidified air rather than let the AC run nonstop (or driving with the windows rolled all the way down).
Clark Semmes, a self-identified hypermiler who commutes from Baltimore to New Carrollton two days a week, said he has seen an improvement on the real-time gas mileage display in his Toyota Prius.
He now gets about 55 mpg on the highway, even though his 6-month-old Prius is only supposed to get 45 mpg.
"I don't go so slow that it would be annoying," said Semmes, a founder of the Mount Washington Green Club.
He also shifts into neutral when going downhill and tries to get behind big trucks, although, he said, "I'm afraid to get too close, so I'm not sure it makes a difference."
Semmes is motivated by his concern for the environment, but he also hypermiles, he said, "because it's cool."
Other drivers gave various reasons for starting to slow down.
George Baca, an anthropologist at Goucher College, maintained a speed of 60 mph in his Volkswagen Jetta to and from Philadelphia last weekend. He usually gets about 325 miles from a full tank when he's driving 75 mph.
For the Philadelphia trip, he only used half a tank to drive 215 miles.
"I'm not really perturbed by gas prices being high," Baca said. "I've always thought it ridiculous that a finite resource was being sold so cheaply in the United States."
But he began driving slower long before gas prices escalated, aware that each gallon expended resulted in pounds of pollution released into the environment.
As he filled up his Dodge Dakota pickup at the White Marsh Costco on Monday, Jim Schaffer explained that he used to drive about 65 mph.
Since gas prices rose a few weeks ago, he has been going about 60 mph.
"I'm noticing a difference," said Shaffer, 56. "At the end of the work week, I've got about an eighth of a tank more."
He said that he and his wife joined Costco for the gas discounts - and they now drive her more fuel-efficient car on weekends. He has also switched from mid-grade to regular gasoline, but filling the pickup Monday still cost $54.
Other drivers said the potential savings on gas wouldn't compensate for time lost by driving slower. "That's what old people do," said Carl Henninger, 27, another Costco customer. "It would definitely make a difference, but I'm not going to change my life for 50 cents a gallon."
Still, the systems administrator from Kingsville said he has been driving a Camry rather than the Dodge Ram pickup he drove before.
Quinn, an administrative aide for the Baltimore County Recreation and Parks Department, has also had a hard time slowing down on her 15-mile commute to her Reisterstown office.
"My car loves to go 40 in a 30-mile zone," she said, adding that she has been pulled over for speeding a few times.
But Quinn, 55, said she has started easing up on the pedal and that it makes the drive more peaceful in addition to saving money. Now she preaches the benefits of hypermiling.
Said Quinn: "It is pretty much common sense."
Sun reporter Julie Scharper contributed to this article.
Hypermiling tips •Avoid accelerating quickly or braking heavily.
•Do not idle excessively.
•Keep tires properly inflated.
•Warm up the engine before driving.
•Remove cargo or cargo racks to reduce weight and air resistance.
Sources: Consumer Reports, hypermiling.com