Hackensack, N.J. ? A year ago, with gasoline selling for more than $4 a gallon, drivers abandoned their gas-guzzling trucks and large SUVs for high-mileage compacts. Now, with prices in the $2.50 range, they’re going back to the big guys, at least in the used-car market.

That sharp U-turn in buying habits has led to a 5.8 percent increase in the price of used cars in the past year — including a 16 percent spike since the beginning of the year — and a shortage of the kinds of vehicles drivers were unloading last summer, according to the Manheim Used Vehicle Value Index.

The biggest price gains since last June were for pickup trucks (up 27 percent) and sport utility vehicles (25.8 percent), while compacts fell almost 10 percent and midsize cars were off by 3.4 percent.

The index has risen for six consecutive months, reaching a 22-month high.