NEW YORK — A summer of expensive gas has drivers increasingly cruising the Web before they hit the road, from tracking the cheapest pump prices online to learning the fuel-saving secrets of “hypermilers.”

David Safely, of Austin, Texas, makes daily visits to GasBuddy .com, a mainstay of gas-saving sites that allows users to compare costs at different stations and post the prices they see.

“I’m not interested in pouring money down the tailpipe,” Safely said. He said putting about a dozen gallons in his 1994 Isuzu Trooper SUV has been costing nearly $50.

“I think it’s important that people are aware of what’s out there so they can plan,” he said.

With gas above $4 a gallon, many people agree.

GasBuddy has about 1.5 million registered users, and up to 3 million unique visitors each day across its 181 local Web sites, co-founder Jason Toews said. He said GasBuddy’s popularity has steadily increased since it launched in 2000, and it attracts the most new users when fuel prices are volatile.

Audrey Blum, of Springboro, Ohio, said she is so price-sensitive that she checks online gas prices nightly before she goes to bed. She said she follows price trends with reports from GasBuddy and the Web site of Speedway SuperAmerica, a gas and convenience store company based near Dayton.

“My goal is always to fill up when prices are as low as possible,” she said.

Offering drivers the chance to hold on to cheaper gas prices is the goal of Miami-based MyGallons, which launched a public Web site June 30. The company says customers who pay an annual membership fee of $30 to $40 can pre-purchase gas at current prices, and actually fill up later when gas is more expensive. The initial price per gallon is based on the average price in the member’s billing ZIP code.

There are risks. Customers gamble that gas prices won’t fall, leaving them stuck with pricey gas.

Safely and Blum are among those who consider themselves hypermilers, drivers who use various on-road techniques to squeeze miles from every drop of gas.

Tricks and tips range from just driving the speed limit and keeping tires properly inflated to timing green lights and coasting to a stop at red ones. More extreme and potentially dangerous steps include drafting behind trucks to lower wind resistance and turning off the engine while going downhill.

On the Web

GasBuddy: www.gasbuddy.com

GasPriceWatch: www.gaspricewatch.com

MyGallons: www.mygallons.com

CleanMPG: www.cleanmpg.com

Ecomodder: www.ecomodder.com