Sean Welch stood at the gas pump, coaxing 10.1 ... 10.2 ... 10.3 gallons into his tank. He had .3 of a gallon to spare -- enough for 35 more miles. Believe it.

Since he had gassed up 28 days earlier, he had driven 1,103 miles in his 2002 Honda Insight -- a hybrid car that even Honda says is doing well to get 61 miles per gallon. Welch's average: 106.2.

Welch is a hypermiler, a term coined by a Chicago man, Wayne Gerdes, to describe those who change their driving behaviors to eke out the most miles from their gas tanks. Gerdes, a veritable Tiger Woods of hypermiling, regularly wins driving competitions and perhaps is best known for driving the 800 miles from Chicago to New York in a hybrid Toyota Prius and using just 8.9 gallons of gas. Mother Jones magazine called him "the most fuel-efficient driver in the world."

Welch divulges the tenets of hypermiling with a seminarian's earnest intensity.

"Mileage, for me, has always been a pursuit," he said.

Welch, 31, lives in Coon Rapids and is founder of a Minnesota hypermilers group, which met for the first time in May. It's not just for hybrid cars; any car is capable of better fuel mileage, depending on the driver.

"Everything that needs to be done as far as modifications is sitting right here," he said, tapping his chest.

Here's what he recommends:

Watch tire pressure. Underpressured tires have more flex, which promotes a smoother ride, but reduces fuel economy because there's more rolling resistance, Welch said. He recommends inflating tires to the PSI noted on the sidewalls, which is the manufacturer's recommended maximum pressure.

People think they're flirting with a blowout, Welch said, then reasonably noted, "If it would blow up at that pressure, the lawyers wouldn't let them put that number on the side of the tire." Buy a tire gauge and check the pressure every other week. (According to automotive instructor Jon Kukachka of Dunwoody College of Technology in Minneapolis, tires at maximum recommended inflation are not unsafe, but will wear faster.)

Plan your trip. "Your best hypermiling is done if you never get behind the wheel," Welch said. But when you have to drive, consolidate your errands and make your first stop the farthest away to allow your engine to warm up before you have to turn it off. In a parking lot, go to the highest point and park facing "out," so you can coast as far as possible when you restart your car.

Read the road. Welch's round-trip commute from Coon Rapids to Golden Valley, where he's an information technology analyst, is 21.9 miles. It would be 17 miles if he used Hwy. 169, but the potential for stop-and-go driving is a mileage killer. "Hypermiling is the management of your momentum," he explained. You never really want to stop, aspiring to drive without brakes, or DWB. Coast whenever possible.

This means maintaining a keen sense of the surrounding conditions. "I spend about as much time looking in my rearview mirror as forward," Welch said. Try to avoid stop signs, "because if there's a stop sign, you must legally stop."

He looks at traffic lights as far ahead as possible. If one has been red for a long time -- a "stale red" -- slowing down might enable you to time your arrival to glide through as it turns green. Likewise, a "stale green" might turn red before you can accelerate through the intersection, so relax, pull to a stop and turn off your car.

Yes, turn off your car. Do so if you figure you'll be stopped for more than 10 seconds. Welch said modern fuel-injected engines use no more fuel to restart than if the car had idled for seven to 10 seconds.

Avoid left turns. "Ninety percent of the time, you have to stop before you make the turn," he said. And, yes, it might make more sense to make three seamless right turns instead.

Watch highway speeds. Hypermilers go at or safely below the speed limit. What's safely? It depends on conditions. Welch knows that even at the speed limit, he might be the slowest car on the highway, so he hugs the white fog line, which makes his car stand out because it appears "out of line" with everyone else. That signals an approaching driver that something is unusual.

Don't draft behind semitrailer trucks. "It's dangerous and we don't promote it," he said, while acknowledging that some hypermilers have been criticized for this. Actually, he added with a smidge of smugness, "For every person who passes me, I get a slight drafting effect. I don't seek it out; it just happens. But all these people who pass me are really just helping me get even better mileage."

Try some gadgets. If you really want to get serious, Welch recommends getting a scan gauge, which tracks each trip's mileage, throttle position, engine temperature, revolutions per minute and more. They cost about $160 and up.

And in the interest of vehicular peace, Welch said, "I have no problem with a person with a big vehicle, if they're using it for a reason. But if I pull alongside these big pickups and the truck bed is empty and shiny, then it's just being used to transport one person."

He can't help but take it a little personally because he doesn't regard hypermiling as a personal pursuit as much as a national cause.

"I don't do it because it's my fuel," he said. "It's everybody's fuel."

Kim Ode • 612-673-7185