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."

liz.kay@baltsun.com

Sun reporter Julie Scharper contributed to this article.

Hypermiling tips
•Avoid accelerating quickly or braking heavily.

•Do not idle excessively.

•Keep tires properly inflated.

•Avoid speeding.

•Warm up the engine before driving.

•Remove cargo or cargo racks to reduce weight and air resistance.

Sources: Consumer Reports, hypermiling.com