Wild 1,012-HP Hennessey Mammoth 1000 TRX 6x6 Enters Production

We first heard of Hennessey’s wild idea to add an extra axle to the already bonkers Ram TRX in 2020. That’s when the tuner teased the Mammoth 1000 TRX 6x6 – a six-wheeled, 1,000-horsepower monster truck monstrosity. This isn’t the company’s first six-wheeled machine, so the announcement wasn’t a surprise. Today, Hennessey has announced that the TRX 6x6 is finally rolling off the production line.

 That’s an eye-watering price, though there is likely nothing comparable to it on the road right now. The truck is massive, measuring 88 inches (223.52 centimeters) wide and nearly 7 feet (2.1 meters) tall. However, those numbers pale compared to the length, which is 283 inches (719 cm).

“Everything on the Mammoth 6×6 is bigger, badder, and more imposing – plus, it’s still super-fast, while being a total powerhouse off-road. It’s the undisputed king of the road,” said John Hennessey, the tuner’s owner.

Propelling the massive beast is the same engine from the Ram TRX – a supercharged 6.2-liter V8. However, Hennessey has added numerous upgrades, including a 2.65-liter supercharger, to crank up the output to 1,012 horsepower (754 kilowatts) and 969 pound-feet (1,313 Newton-meters) of torque. The TRX’s stock engine is no slouch, pumping out 702 hp (881 kW) and 650 lb-ft (516 Nm) of torque straight from the factory, but that’s rarely enough to satisfy Hennessey.

The tuner added new supercharger pulleys, upgraded spark plugs, high-flow fuel injectors, a crankcase ventilation system, software calibration upgrades, and more. Hennessey also added the third axle with a lockable differential that required extending the wheelbase and bed. The truck also features new front and rear bumpers, extra LED lighting, and 20-inch 10-spoke Hennessey wheels with 37-inch off-road tires wrapped around them.

There’s a front leveling kit, upgraded electronic fold-out steps, embroidered headrests, Hennessey and Mammoth badging, and a two-year warranty. The truck is the largest that Hennessey has ever built, and with only 12 planned for production, it’ll be a rare vehicle. And it’ll be expensive, with each costing in excess of $449,550.