SANTA MONICA--Edmunds.com recently released the most fuel-efficient vehicles for the 2004 model year. Not surprisingly, the Honda Insight and Toyota Prius, the only two gas-electric hybrid vehicles on the market, top the list.There is a wide gap between first and 10th place—the Insight and Prius are rated at 60 miles per gallon during city driving compared to the 10th place vehicles at 29 mpg.Edmunds.com calculated the average fuel economy for 2004 model year vehicles at 19 miles per gallon in city driving and 26 mpg on highways. The market will change drastically, according to Edmunds.com, as more manufacturers introduce hybrid vehicles. Hybrid versions of the Ford Escape, Chevy Silverado, Dodge Ram, GMC Sierra, Honda Accord, Lexus RX400h and Toyota Highlander are planned for the model year 2005.Edmunds.com has also computed the average fuel expense of all vehicles at $1,310, assuming 15,000 miles driven per year. Cars average $1,178 in fuel expenses while trucks, SUVs and minivans average $1,606.The most fuel-efficient vehicles are:(1) Honda Insight (2) Toyota Prius* (3) Honda Civic Hybrid (4) Volkswagen Golf TDI Volkswagen Jetta TDI Volkswagen New Beetle TDI (5) Honda Civic HX (6) Toyota Echo (7) Toyota Corolla (8) Scion xA (9) Scion xB (10) Dodge Neon Pontiac Vibe Toyota Celica GT* Toyota MatrixEdmunds.com compiled the list based on the Environmental Protection Agency's (EPA) miles per gallon ratings for city and highway travel, using the EPA's combined fuel economy formula. No all-electric or natural gas vehicles were included. All ratings apply to base models equipped with a manual transmission, except where indicated otherwise with a single asterisk (*).