With 1,032 hp and 947 lb-ft of torque, the new Hennessey Maximus adds 255 hp and 267 lb-ft over the Ram 1500 Rumble Bee SRT on which it is based. The stock truck already produces 777 hp and 680 lb-ft from its supercharged 6.2-liter HEMI V8, but Hennessey pushes those numbers substantially higher with a high-capacity intercooler, larger intake tube and proprietary engine calibration.
Hennessey gives the Ram Rumble Bee SRT a 1,032-hp makeover
Hennessey displayed the first pre-production Maximus at SRT Performance Engineering Day in Detroit. Customer production should begin during the first quarter of 2027, although the Texas tuner has not announced pricing or production numbers. Each truck will include a three-year/36,000-mile limited powertrain warranty.
The performance estimates place the Maximus firmly in supercar territory. Hennessey expects it to accelerate from 0 to 60 mph in 3.0 seconds and complete the quarter mile in 10.9 seconds. The standard Rumble Bee SRT needs 3.4 seconds and 11.6 seconds respectively.
Top speed represents the more ambitious target. Ram aims for 170 mph with the factory Rumble Bee SRT, while Hennessey estimates that the Maximus could reach 200 mph. The company has not yet confirmed that figure through a final top-speed test.
Hennessey designed the Maximus as a street truck rather than another lifted off-road build. It retains the Rumble Bee’s four-corner air suspension with a lowered setting and rides on 22-by-12-inch Hennessey wheels wrapped in 325/40R22 performance tires.
The VenomAero package adds an aggressive front splitter, side skirts and a huge removable rear wing inspired by Hennessey’s 1999 Dodge Viper Venom 650R. Hennessey says drivers will need to remove the wing when attempting the estimated 200-mph top speed to reduce aerodynamic drag. Carbon-fiber components and a hard tonneau cover complete the exterior changes.
Inside, Hennessey adds leather and Alcantara upholstery, Maximus branding and dedicated floor mats, maintaining the performance-focused character without stripping away the Rumble Bee’s everyday usability.
The historical inspiration is easy to recognize. Ram’s original SRT-10 brought Viper power to the pickup segment in the 2000s, producing 500 hp and reaching 154 mph. The new Rumble Bee SRT already surpasses those figures with 777 hp and a targeted 170-mph top speed.
The Maximus takes that same street-truck philosophy much further. With more than twice the horsepower of the old SRT-10 and a projected 200-mph top speed, Hennessey is effectively turning Ram’s newest muscle pickup into something capable of challenging serious performance cars.