If paying $4 a gallon at the pump doesn’t sour you on driving a full-sized sport utility vehicle, now is the time to buy one.

Dealers are offering tempting incentives on trucks and full-sized SUVs, and used models are on sale at clearance pricing. That’s primarily because many motorists are abandoning the gas guzzlers for compact cars or hybrids that get better gas mileage.

“The more there is, the less they’re worth. Supply and demand,” said Gerry Perrault, new car manager at Serafini Nissan Volvo in Vestal. “Everyone’s looking to bail out of them and it just brings the value of them down significantly.”

As gas prices approached and surpassed $4, major shifts occurred in the marketplace. Nationally, automakers are struggling financially and slowing production of fuel-consuming vehicles, including the formerly popular Ford F-150 truck. Ford, GM and Chrysler all recently reported double-digit declines in full-sized SUV and truck sales.

Meanwhile, cars are flying off dealers’ lots, and some prices are climbing because of increased demand.

“I’ve never sold more cars here — ever,” Perrault said. “I wish I had more inventory.”

Today, a shopper who peruses the lot of a used car dealership can see recent model SUVs selling for only a few thousand dollars more than an older-model gas-sipping sedan.

For example, at Mark’s Auto Sales in Endicott, you can buy a 2004 Nissan Sentra with 70,000 miles for about $8,000. Or, you can buy a 2005 GMC Envoy with 42,000 miles for a little more than $10,000.

The Sentra, with a highway rating of about 27 miles per gallon, is priced about $1,000 more than it would have been six months ago, a dealer said. Meanwhile, book value on the SUV, which gets about 19 mpg on the highway, is about $18,000 — 44 percent higher than today’s actual selling price.

“I’ve been at it 30 years and I’ve never seen a market swing of that magnitude,” said Mark Ogozaly, owner Mark’s Auto Sales on Harrison Avenue.

Though nationally, SUV sales have slowed, Ogozaly said he has sold 50 percent more of the vehicles this year compared to last year. For some customers, the reduced price of a loaded SUV is tempting, especially since months ago the traditionally expensive vehicles may have been out of a buyer’s price range, he said. For other customers, who might have large families or more space needs, lifestyles can’t always be squeezed into a small vehicle.

“Not everybody can drive around in a subcompact,” Ogozaly said.

Endwell resident Jim Coyle recently spent about $10,000 on a used 2006 Buick Rainier at Mark’s. Spending more for a hybrid vehicle wasn’t worth it to Coyle, he said, since he figured it would take 10 years before his gas savings broke even with the cost of the fuel-efficient car.

“We only drive like 10,000 miles a year,” Coyle said. “It’s comfortable; it’s not economical for sure. It only gets 14 miles a gallon.”

Not only will full-sized SUV shoppers get a good price, but they’ll also have a lot of choices, unlike customers looking for cheap used cars. The used car lot at Serafini Nissan Volvo is jammed with SUVs and trucks, making up about 75 percent of the inventory, Perrault said.

Manufacturers have raised new cars prices a few hundred dollars because of the demand, he said. Two years ago, the dealership sold three trucks or SUVs to every car. Today, five cars are sold for every one truck or SUV.

“Our inventories are dangerously low right now because of it,” he said.

New car dealers are offering specials, including cash back and gas deals for customers who buy trucks and SUVs. At Miller Dodge, buyers who pick a vehicle from the Dodge line will pay no more than $2.99 for a gallon of gasoline for three years. Buyers interested in a Nissan Titan truck could be offered zero percent financing and a $5,000 rebate. The truck, which starts at $25,000, gets 17 mpg.