The RAM 2500/3500 Mega Cab II (DT) series, specifically the 3500 model equipped with the 6.7-liter Cummins turbocharged diesel engine producing 400 horsepower and paired with a six-speed automatic transmission and a four-wheel drive (4×4) system, represents a significant offering in the heavy-duty pickup truck segment. Introduced for the 2019 model year and continuing through 2025, this configuration caters to buyers requiring substantial towing and hauling capabilities combined with a degree of refinement. This variant, designated as a Single Rear Wheel (SRW) model, occupies a central position within the 2500/3500 lineup, bridging the gap between lighter-duty configurations and the more specialized dual-rear-wheel (DRW) models.
Technical Specifications
| Brand | RAM |
| Model | 2500/3500 |
| Generation | 2500/3500 Mega Cab II (DT) |
| Type (Engine) | 3500 6.7 Cummins TD (400 Hp) 4×4 Automatic SRW |
| Start of production | 2019 |
| End of production | 2025 |
| Powertrain Architecture | Internal Combustion engine |
| Body type | Pick-up |
| Seats | 5-6 |
| Doors | 4 |
| Fuel Type | Diesel |
| Weight-to-power ratio | 9.2 kg/Hp, 109.2 Hp/tonne |
| Weight-to-torque ratio | 3.4 kg/Nm, 295.9 Nm/tonne |
| Power | 400 Hp @ 2800 rpm |
| Power per litre | 59.8 Hp/l |
| Torque | 1084 Nm @ 1800 rpm (799.52 lb.-ft. @ 1800 rpm) |
| Maximum engine speed | 3200 rpm |
| Engine layout | Front, Longitudinal |
| Engine displacement | 6690 cm3 (408.25 cu. in.) |
| Number of cylinders | 6 |
| Engine configuration | Inline |
| Cylinder Bore | 107 mm (4.21 in.) |
| Piston Stroke | 124 mm (4.88 in.) |
| Compression ratio | 16.2:1 |
| Number of valves per cylinder | 4 |
| Fuel injection system | Diesel Commonrail |
| Engine aspiration | Turbocharger, Intercooler |
| Engine oil capacity | 11.4 l (12.05 US qt | 10.03 UK qt) |
| Coolant | 20.8 l (21.98 US qt | 18.3 UK qt) |
| Kerb Weight | 3664 kg (8077.74 lbs.) |
| Max. weight | 5579 kg (12299.59 lbs.) |
| Max load | 1915 kg (4221.85 lbs.) |
| Trunk (boot) space – maximum | 1628 l (57.49 cu. ft.) |
| Permitted trailer load with brakes (12%) | 10913 kg (24059.05 lbs.) |
| Length | 6348 mm (249.92 in.) |
| Width including mirrors | 1994 mm (78.5 in.) |
| Height | 2036 mm (80.16 in.) |
| Wheelbase | 4074 mm (160.39 in.) |
| Front track | 1719 mm (67.68 in.) |
| Rear (Back) track | 1704 mm (67.09 in.) |
| Minimum turning circle (turning diameter) | 15.6 m (51.18 ft.) |
| Approach angle | 18.5° |
| Departure angle | 25.7° |
| Ramp-over (brakeover) angle | 20.3° |
| Drive wheel | All wheel drive (4×4) |
| Number of gears and type of gearbox | 6 gears, automatic transmission Aisin |
| Front suspension | Independent multi-link suspension |
| Rear suspension | Leaf spring |
| Front brakes | Disc |
| Rear brakes | Disc |
| Assisting systems | ABS (Anti-lock braking system) |
| Tires size | 235/80 R17; 275/70 R18 E; 285/60 R20E |
| Wheel rims size | 6J x 17; 8.0J x 18; 8J x 20 |
INTRODUCTION
The RAM 2500/3500 Mega Cab II (DT) series, launched in 2019, represented a comprehensive redesign of the heavy-duty RAM lineup. This generation, internally designated ‘DT’, brought significant improvements in interior refinement, technology, and capability. The 3500 model, particularly when equipped with the 6.7-liter Cummins diesel, is geared towards customers who prioritize substantial towing and payload capacity. The Mega Cab configuration offers a significantly larger rear seat area than standard crew cab models, making it popular for families or those frequently transporting passengers alongside work duties. The combination of the 400 horsepower Cummins engine and the Aisin six-speed automatic transmission provides a balance of power, efficiency, and usability for demanding tasks.
Powertrain & Engine Architecture
At the heart of this variant lies the 6.7-liter Cummins inline-six diesel engine. This engine, known for its durability and longevity, utilizes a cast iron block and head. The 400 horsepower version, introduced with the DT generation, benefits from a revised turbocharger and fuel injection system. The engine employs a Bosch common-rail fuel injection system, delivering highly pressurized fuel directly into the cylinders for optimized combustion. The valvetrain features four valves per cylinder, enhancing breathing and contributing to the engine’s power output. The Aisin six-speed automatic transmission is a robust unit specifically designed to handle the high torque output of the Cummins engine. It features electronically controlled shifting and a tow/haul mode that optimizes gear selection for towing and hauling applications. The transmission’s gear ratios are tailored to provide strong low-end torque for pulling heavy loads, while still offering comfortable highway cruising.
Driving Characteristics
The 400 horsepower Cummins paired with the Aisin automatic delivers a markedly different driving experience compared to the gasoline-powered RAM 2500/3500 models or even lower-output Cummins variants. While not as quick off the line as a gasoline engine, the diesel provides a broad, flat torque curve that makes it exceptionally capable when towing or hauling. The Aisin transmission shifts smoothly and decisively, and the tow/haul mode effectively manages gear selection to prevent excessive shifting on grades. Compared to the 350 horsepower version of the same engine, the 400 hp variant offers a noticeable increase in responsiveness, particularly when accelerating with a load. The automatic transmission, while convenient, doesn’t offer the same level of control as a manual transmission, but it simplifies operation for a wider range of drivers.
Equipment & Trim Levels
The 3500 6.7 Cummins Automatic SRW was available in a variety of trim levels, including Tradesman, Big Horn/Laramie, Limited, and Longhorn. The base Tradesman trim offered a functional interior with vinyl upholstery and basic amenities. Higher trims, such as the Laramie and Longhorn, featured leather upholstery, wood trim, premium audio systems, and advanced safety features. Standard equipment across most trims included air conditioning, power windows and locks, and a basic infotainment system. Optional extras included a premium sound system, navigation, a rear-seat entertainment system, and various driver-assistance technologies like adaptive cruise control and lane departure warning.
Chassis & Braking
The RAM 2500/3500 utilizes a heavy-duty chassis designed to withstand the stresses of demanding work. The front suspension features an independent multi-link setup, providing a comfortable ride and good handling. The rear suspension employs a traditional leaf spring design, optimized for load-carrying capacity. Braking duties are handled by disc brakes on all four wheels, providing ample stopping power even when heavily loaded. An Anti-lock Braking System (ABS) is standard. The SRW configuration utilizes a narrower track width compared to the DRW models, resulting in slightly less stability when towing extremely heavy loads, but offering improved maneuverability in tight spaces.
Market Reception & Comparison
The RAM 2500/3500 with the 6.7-liter Cummins diesel engine consistently received positive reviews from automotive critics. The engine was praised for its power, durability, and fuel efficiency (relative to its class). The Aisin automatic transmission was also lauded for its smooth operation and ability to handle the engine’s torque. Compared to the gasoline-powered RAM 2500/3500 models, the diesel offered significantly better fuel economy when towing or hauling. Compared to competitors like the Ford Super Duty and Chevrolet Silverado/GMC Sierra, the RAM 2500/3500 was often cited as offering a more comfortable ride and a more refined interior.
Legacy
The 6.7-liter Cummins diesel engine has a long-standing reputation for reliability and longevity. Properly maintained, these engines can easily exceed 200,000 miles. The Aisin transmission is also known for its durability. On the used car market, the 2019-2025 RAM 3500 6.7 Cummins Automatic SRW holds its value well, reflecting its capability and reputation. These trucks remain a popular choice for buyers seeking a heavy-duty pickup that can handle demanding tasks while providing a comfortable and refined driving experience. Common maintenance items include regular oil changes, fuel filter replacements, and coolant flushes. The electronic components, while generally reliable, may require attention as the vehicle ages.
