As commercial cargo vans shift to unibody from truck-based platforms, one wonders how robust these new vans are. During test drives, we discovered they come in efficient, spacious and comfortable packages yet still have room for refinement.

Last month, ENR took a spin in a Fiat Ducato-based 2016 Ram Pro-Master 1500 cargo van at the truckmaker’s proving grounds in Chelsea, Mich. With a 136-in. wheelbase and low roof, the $42,425 van sported Ram’s 3.0-liter, inline-four-cylinder EcoDiesel engine and six-speed automated manual transmission (AMT). This setup has a class-leading highway fuel economy in the low to mid-20s mpg, Ram claims.

We pulled 500 lb of ballast in the cargo hold and a 2,500-lb trailer as the ProMaster pulled away with confidence and carried us quickly to highway speeds. The AMT’s robotic clutch is a tad noisy and slow, resulting in a rattling torque loss between shifts. Even so, AMTs are rapidly growing in fleets due to their ease of use, experts say.

Despite fuel efficiency, Ram’s 4,420-lb max payload, 5,100-lb towing capacity and 463-cu-ft cargo space lag behind other full-size vans. The conventional Chevrolet Express and GMC Savana have class-leading towing of 10,000 lb, while Mercedes-Benz and Freightliner rule payloads with Sprinter’s 5,508-lb rating and 586.1 cu ft of cargo room.

Ram makes up for these shortcomings with a front-wheel-drive chassis that provides a low and flat loading floor and retail prices that start at $30,165, less than all but the Nissan NV. For more details, see the story on p. CBQ16 and watch a video review on ENR.com.