The Ram 1500 EcoDiesel's superior fuel economy ratings of 20 miles per gallon overall and 27 mpg on the highway helped push it over the top in the competitive field, edging the second-place Ram 1500 V8 and the third-place General Motors Co (>> General Motors Company) Chevrolet Silverado 1500.

In Consumer Reports' road tests, the Ram EcoDiesel scored an 82, followed by the Ram 1500 V8 at 81, the Silverado and the Sierra at 80, Ford Motor Co's (>> Ford Motor Company) F-150 EcoBoost V6 at 70, and the F-150 V8 at 69.

"The continued interior and powertrain improvements make the Ram a particularly well-rounded choice for most consumers," the magazine said in a statement.

Pickup trucks are the keys to profit for American automakers.

Later this year, Ford will introduce an F-150 with more aluminum and improved fuel economy. The current V8 version gets 15 mpg overall and 22 mpg on the highway, according to Consumer Reports.

Toyota Motor Corp's (>> Toyota Motor Corp) Highlander took the top two spots in its category. The hybrid version was first among midsize SUVs and the gasoline version second.

Chrysler's Jeep Grand Cherokee diesel version was third in the ratings, followed by Hyundai Motor Co's (>> Hyundai Motor Co) Santa Fe and Nissan Motor Co's (>> Nissan Motor Co Ltd) Murano.

Toyota last week announced that it would increase production of the Highlander at its plant in Indiana by investing $100 million and adding 300 jobs by the summer of 2016.

Consumer Reports says it gathers at least a year of field data on a vehicle's reliability before it offers a "recommended" rating.

Among full-size pickup trucks, Consumer Reports recommends the Ram 1500 gasoline V8, the Ford F-150 V8, and the Toyota Tundra. The Ram EcoDiesel and the both the Silverado 1500 and the GMC Sierra are too new on the market to have comparative reliability ratings, it noted.

Through July, the F-150 pickups were the top-selling vehicles in the U.S. market, followed by the Silverado, the Toyota Camry sedan and the Ram pickups, according to Autodata Corp.

Chrysler is a unit of Fiat SpA (>> Fiat SpA).

(Reporting by Bernie Woodall; Editing by Dan Grebler)