By DEE-ANN DURBINDETROIT (AP) â¿¿ U.S. car and truck sales are expected to hit their highest level in nearly six years in March, as buyers armed with tax refund checks were lured by flashy new vehicles and low interest rates. Auto companies release U.S. sales figures Tuesday. Analysts predict total sales of nearly 1.5 million cars and trucks, a number not seen since May 2007. That's almost double the 855,000 vehicles sold in March 2009, the low point for sales during the economic downturn, according to Ward's AutoInfoBank. Sales are expected to be up 3 to 5 percent over last March. Alec Gutierrez, a senior market analyst with the car pricing company Kelley Blue Book, said the improving job market is boosting sales. The number of Americans seeking unemployment benefits fell to a five-year low during March. Low interest rates are also making new-car purchases more appealing, Gutierrez said. The average rate for a 60-month new-car loan is now 4.12 percent, down from 4.52 percent at this time last year, according to Bankrate.com. And Gutierrez says tax refunds can also spur purchases. The average federal tax refund this year is nearly $3,000, or enough to cover the down payment on a three-year lease of a Toyota Camry hybrid or a BMW 3-Series sedan. Full-size pickup truck sales are expected to rise nearly 15 percent in March, following big gains in February, Kelley Blue Book said. Construction companies are rapidly replacing their truck fleets as the economy improves and they win more business. Gutierrez said incentive deals â¿¿ such as the $7,500 cash back now offered for the Chevrolet Silverado pickup â¿¿ are helping truck sales, and should continue for a while. General Motors, Ford and Chrysler each have a healthy supply of trucks for sale and GM wants to clear out older models before introducing its new Chevrolet Silverado in a few months.