Toyota reported another drop in sales of its hybrid sedan, Prius, and stated the slump was due to inability to keep up with demand. 

Ford, which offered a zero-percent financing loan on Ford Escape and Mercury Mariner hybrid SUVs in April, said sales of the two soared 115%. But will this trend continue as gas prices escalate, or will fuel economy eventually outweigh loan incentives?

Will Auto Loan Incentives and Rebates Outweigh Fuel Efficiency?

Financing for gas fillup or for an auto loan?

Auto makers shift gears to offer consumers more fuel efficient cars. According to Ford Motor, gas prices - for the first time - are affecting sales of its F-150 pickup, the best selling vehicle in the United States. Ford's F-series sales were down 9.3% in April from a year ago. Sales of Ford Explorer, which has been the top-selling SUV, were off a dramatic 42%. In April, Explorer was outsold by the smaller Toyota RAV4 SUV.

During April, gas prices went up nearly 40% and automaker sales reflected how fuel efficiency is becoming a major selling point than in previous years. Fuel economy may now override the marketability of low loan interest rate or cash back incentives as a way to lure buyers.

According to AutoData, overall sales were down 4.2%, while gas-hungry truck sales were down 7%. 

Sales of the more fuel efficient Nissan Sentra; however, increased 20%, even though this particular model will be phased out in fall.

U.S. automakers will need to shift focus on less gas guzzling autos and away from truck sales. Ford's overall sales were off 6.8%. Its car sales rose 8.3% but couldn't offset a 14.8% drop in trucks.

Daimler Chrysler sales were down 6.2%, led by an 18.1% decline in trucks.

General Motors; however, felt a reverse loss. Its sales fell 10.8%, most of which resulted from a 21% decline in car sales. Truck sales were down 2.7% despite new SUVs such as the Chevy Tahoe, which had a 24% sales increase.