Updated

With gasoline around $4 in much of the nation, fuel economy has never been more important to pickup truck buyers. That's why engineers who worked on revamping Chrysler's Ram put it at the forefront of their work.

Chrysler won't reveal the exact figures, but the company says the new Ram will have the best mileage of any full-size pickup when equipped with either a V-6 or V-8 engine.

Along with more efficient engines, the 2013 Ram has better aerodynamics, an eight-speed automatic transmission, technology to shut the engine down at stop lights, and other improvements to boost mileage.

The truck, due in showrooms in September, will be introduced Thursday at the New York International Auto Show:

UNDER THE HOOD: Ram buyers get a choice of a new 3.6-liter, 305 horsepower V-6 or the venerable 5.7-liter, 395 horsepower Hemi V-8. The eight-speed transmission, which raises fuel economy because the engine works less at highway speeds, comes standard with the V-6 and as an option on trucks with the Hemi. There's also the stop-start system, a first in big pickups. It shuts off the engine when the truck comes to a complete stop, restarting it when the driver's foot comes off the brake. There's also a system that keeps the transmission fluid at 190 degrees, reducing friction. And the truck gets electric power steering. The old one ran the steering off the engine, creating drag and cutting mileage.

OUTSIDE: The revamped truck keeps the aggressive look of the current version. Its cab looks like a semi, and it has an intimidating presence. The pickup gets a larger grille, some new lights and optional running boards. The bigger grille has shutters that close when the engine doesn't need as much air, cutting wind drag and raising gas mileage. The Ram borrows an air suspension from the Jeep Grand Cherokee. It's an option that raises and lowers the pickup's height to cut down on wind resistance.

INSIDE: Chrysler says it's redesigned with upgraded materials. It has new heating and air conditioning controls, new shifter controls and added touch-screen systems.

FUEL ECONOMY: Chrysler won't release numbers yet, but it did make the promise of best-in class fuel economy. It also promised that the new V-6, when paired with the eight-speed transmission, will get at least 20 percent better gas mileage than the current model. That would put the new V-6 around 24 mpg on the highway, up from the current 20. It also promised that the V-8 version with the eight-speed transmission would get at least 10 percent better mileage than the current truck, taking it to around 22 mpg on the highway.

PRICE: Chrysler hasn't released the number yet, but it is likely to be more than the current truck. The base 2012 two-wheel-drive Ram with a V-6 starts at $21,820.

CHEERS: Buyers want to save money on fuel, and Chrysler has gone to great lengths to raise the Ram's gas mileage. It's also increased the horsepower and towing capacity of the V-6 engine, making it more appealing.

JEERS: The truck doesn't look much different from the old one, and it faces stiff competition later in the year from a new Chevrolet Silverado and GMC Sierra.