Ram's powerful 2500 and 3500 Heavy-Duty trucks return for 2021 with more to like than ever before. Across the HD range, buyers can choose between a gasoline-fueled 6.4L Hemi V8 and two iterations of a 6.7L Cummins inline 6-cylinder diesel. All gasoline engines are mated to an 8-speed automatic transmission, while a 6-speed automatic handles the additional torque of the diesels. A 6-speed manual is also available. The 6.4L Hemi V8 makes 410 horsepower and 429 lb-feet of torque. With the 6-speed manual, the Cummins is rated at 370 horsepower and 850 lb-feet of torque at just 1,700 rpm. When mated to the 6-speed automatic transmission, output jumps to 400 horsepower and an astonishing 1000 lb-feet of torque. Diesel Rams employ a Ram Active Air intake system that draws more cool air from the front of the truck for more power in hot temperatures or at high altitude. Ram HDs can be ordered with either rear-wheel drive or 4-wheel drive. In 4-wheel-drive models, a front-axle disconnect system can help improve fuel economy. The Ram 3500 utilizes a Hotchkiss leaf-spring rear suspension, while 2500s have replaced leaf springs with a 5-link coil spring setup. Front suspension is now courtesy of a 3-link system. 2500s can be optioned with heavy-duty air suspension in place of the coil springs, which allow for driver-controlled load-leveling with precise, individual adjustment. Leaf-sprung 3500 dual-rear-wheel trucks with maximum tow packages also feature the air suspension system. Ram understands that its trucks must last a lifetime. To stand behind them, Ram offers a 5-year, 100,000-mile warranty on all its powertrains. On the interior, Ram HD trucks have been reconfigured to provide increased creature comforts. Available amenities include soft-touch instrument panels and door trim, 2-tone upholstery and contrasting stitching. Wood and metal inlays accent the interior and a largest-in-class 12-inch full-color touchscreen display serves as central command for the Ram HD. Heated and ventilated seating and a heated steering wheel are also available. Buyers can choose between bucket seats or a 40/20/40 bench configuration. In either case there's a multi-media port in the center with USB, SD and auxiliary inputs. Seven trim levels are offered: Tradesman, SLT, Big Horn, Laramie, Laramie Longhorn, Power Wagon and Limited. These can be configured with either 2- or 4-wheel drive, 2-door Regular-cab, 4-door Crew-cab or 4-door Mega cabs. Two bed lengths are offered, a 6'4" or 8'. Ram's patented Ram Box can be equipped in several trims, adding a secure storage system in the sides of the bed. Each Ram HD offers a different set of interior appointments and equipment that can be tailored to fit basic work needs or provide a relatively luxurious cabin. Two different UConnect systems with the 12-inch touchscreen are offered both with Bluetooth hands-free connectivity. The top system also provides wireless Internet connectivity, as well as HD Radio and SiriusXM compatibility. Top Laramie models offer impressive luxury and convenience, including a power-sliding rear window, leather upholstery, a heated steering wheel, dual-zone temperature control, an overhead console, a universal garage-door opener and special in-floor storage. Available features include an Alpine 10-speaker premium audio system, rain-sensing wipers and projector beam headlamps.