With a big boost from its fuel-mileage-leading status, the Ram 1500 EcoDiesel pickup has moved to the top of the auto industry’s light-duty diesel sales chart.

The Ram has raced past perennial leaders from Volkswagen – the Jetta, Golf and Passat TDI diesels.

Through the end of May, Ram has sold 24,608 ecodiesel pickups, followed by the VW Jetta with 9,840 car sales, VW Passat 9,257, VW Golf 4,034, BMW X5 2,843, VW SportWagen 2,434, Audi Q5 2,082, Porsche Cayenne 1,848, Mercedes-Benz GLK 1,821, Mercedes GL-Class 1,631, Chevrolet Cruze 1,570, BMW 3-series 1,553.

These are not to be confused with the sales of Cummins, Powerstroke and Duramax heavy-duty diesels; three-quarter and one-ton trucks of Ford, Chevy (GMC) and Ram stage their own competitive sales race in that bigger category.

The Ram 1500 delivered to me was the dressed-up Laramie Longhorn Crew Cab edition. Even in its four-wheel-drive configuration, it carries an EPA highway estimate of 27 miles per gallon (29 for rear-wheel drive), best among half-ton pickups.

We drove to Boulder, up and around the increasingly crowded University of Colorado campus and back to Greeley, averaging 24.2 mpg. Daily in-town drives and a bit of offroad maneuvering dropped the overall average to 22.7 mpg, which also included a drive to Parker to test the barbecued steaks of Daniel Hansen.

The Ram engine, also available in the Jeep Grand Cherokee, is a 3.0-liter V-6 turbodiesel built by VM Motori of Cento, Italy, developing 240 horsepower and 420 lb.-ft. of torque. It performs with strong midrange torque and smooth shifts from the German-developed 8-speed automatic transmission, controlled from a dial on the dash. Just beneath that are buttons for the electric shift-on-the-fly transfer case between two-wheel, four-wheel and low-range settings. The half-ton crew cab offers 9,250 pounds of tow capacity.

The pickup provides a very comfortable, controlled ride, based on its coil springs at all four corners. Typically, half-tons use coils in front and stiffer leaf springs at the rear. The Ram offers an electronically controlled air suspension as an option, and parent company Fiat Chrysler Automobiles believes most truck buyers, if seeking best hauling capability, will opt for the company’s 2500 and 3500 units with strong leaf springs.

The Laramie Longhorn edition features wide, supportive front seats, heated and cooled, with lumbar support. The cattle tan interior is finished with lots of leather and trimmed with light wood atop the display screen and around the air/audio controls of the center stack. Dual glove boxes and a large center console bin boost storage possibilities.

The Ram’s short bed (5-foot-7 length) is complemented with Ram boxes for lockable cargo along the upper sides of the pickup bed. A step can be lowered from the left corner of the rear bumper for ease of access into the box; it seems not as handy as those steps built into the corners of both sides of the Chevy Silverado bumpers.

The ecodiesel engine and RamBox cargo compartments on both sides of the pickup bed boosted sticker price on the Ram 1500 to $55,970. Among the many amenities not aforementioned are deep cherry red exterior, Laramie Longhorn instrument cluster, remote start, backup camera, UConnect 8.4AM/FM/navigation and integrated voice command with Bluetooth, nine amplified speakers with subwoofer, leather-wrapped and heated steering wheel, power adjustable pedals, rear power sliding window and heated second-row seats.

Here are the specifications for the 2015 Ram 1500 Longhorn EcoDiesel Crew Cab 4X4:

• Capacity Half-ton diesel pickup, 5-passenger
• Wheelbase 140.5 inches
• Length 209 inches
• Width 79.4 inches
• Height 76.6 inches
• Curb Weight 5,895 pounds
• Track 68 inches front, 67.9 rear
• Ground Clearance 9.9 inches
• Turn Circle 45.1 feet
• Drivetrain Four-wheel-drive
• Engine 3.0-liter V-6 turbodiesel
• Horsepower/Torque 240/420
• Transmission 8-speed automatic
• Steering electric power rack-and-pinion
• Suspension independent coil front, multilink coils rear
• Fuel mileage estimate 19/27
• Fuel mileage average 22/7
• Fuel Tank 26 gallons, diesel
• Wheels 20-inch
• Tires Goodyear Wrangler P275/60R20
• Cargo Volume 5-foot-7 bed
• Warranty 3 years/36,000 miles basic, 5/100,000 powertrain

Competitors 2016 Nissan Titan XD diesel

Assembly Plant Warren, Mich.

Parts Content U.S./Canadian 61%, Mexico 23%, Germany 5%, Italy 5%

Base Price of Lowest Model $30,940; Base Price of Review Model $50,080; Destination Charge $1,195; Sticker Price $55,970.