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The Hennessey Mammoth 400 sends the Hemi out in style

The latest Ram 1500 will be the last time we see a gas-powered Hemi in a production truck

Hennessey Mammoth
Hennessey

Like it or not, the “EV-olution” of automobiles is well underway. And though it seems difficult to argue against, there are some genuine downsides to going green. As the ice age of the autoverse draws to a close, we will have to watch as one of the most storied fossil-fueled engines rides into extinction.

Chrysler’s Hemi has been around since the 1950s in one form or another and provided power to a myriad of Dodges, Plymouths, Chryslers, Jeeps, and more. Unfortunately, the latest Ram 1500 will be the last time we see a gas-powered Hemi in a production truck. Like us, world-famous tuner John Hennessey is sad to see the mythical motor take its leave and decided to say goodbye, fittingly, with the Mammoth 400.

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The Mammoth 400 gets its own unique suspension

Hennessey Mammoth 400
Hennessey

The main upgrades for the Mammoth 400 begin with a trick suspension setup. Although the base Ram is a competent off-roader, the Mammoth 400 aims at improving on-road performance. The Mammoth gets a set of specialized shocks courtesy of Hennessey’s partnership with Fox Factory specifically for this truck.

Fox Factory is most known for its plethora of off-road racing suspension pieces, but in this case, those shocks combine with a Ridetech lowering kit to allow the big Mammoth to drop its center of gravity significantly. Beyond just better and more predictable handling, the lowering kit gives Hennessey’s truck a noticeably more aggressive look.

The Mammoth 400 gets a carbon fiber aero kit

Hennessey Mammoth 400
Hennessey

A head-turning carbon fiber aero kit, including a revised front bumper, rear bumper, and side skirts, complements the dropped ride height. Fender flares over the wheel wells look factory-spec and make the Mammoth appear much wider than the stock truck. The loan power upgrade included with the  Mammoth package is its Borla Sport exhaust, which funnels the Hemi’s glorious serenade through a set of beautiful carbon fiber exhaust tips.

The Mammoth 400 can be had in three American colors

Hennessey Mammoth
Hennessey

Owners can choose from three distinct (and patriotic) colors: Viper Red, Viper White, or GTS Blue. In any case, a set of full-length stripes is included, which hark back to Hennessey’s early success with Chrysler’s other legendary nameplate, the Dodge Viper. Beyond paint, the Mammoth’s big 22-inch rims can be optioned in Gunmetal or Gloss Black to finish off the big truck’s racy look. 

Only 250 Mammoth 400s will be built

Hennessey Mammoth 400
Hennessey

Although 400 would seem like the most sensible number, Hennessey has elected to produce only 250 editions of the Mammoth. Each truck comes with its own serial-numbered engine bay plaque to authenticate and commemorate the Mammoth 400’s identity as the last Hemi truck.  Beyond just the serial number, Hennessey offers its own 3-year/36,000-mile warranty with the $39,995 price tag (on top of the cost of the base Ram 1500).

The Hemi is about as patriotic as eating an apple pie watching a rerun of the Super Bowl on the Fourth of July. And with that notion in mind, Hennessey’s CEO leaves us with this thought regarding his Mammoth 400:

Our MAMMOTH 400 Ram celebrates American independence with patriotic colors combined with the ‘fireworks’ that only the Hemi V8 engine can deliver!

We couldn’t agree more.

Lou Ruggieri
A lifelong lover of cars, Lou contributes to Motor Trend, Hot Cars, Auto & Truck Connection, and the PowerAutoMedia Group.
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