GM Teases 8.3-liter 'Mongoose' Turbo-Diesel V8

Following last week’s promotion of the new V8s that will replace some of the brand’s more contentious powertrains, General Motors has elected to tease the new Duramax “Mongoose” engine. Despite being named after a small predatory mammal, the motor is a monstrous 8.3-liter turbo diesel.

As with the new small blocks, the Duramax V8 will see action in the updated Chevrolet Silverado and GMC Sierra. The only difference is that the gasoline engines will premiere in the 1500 models, whereas the big turbo diesel will be installed on the HD variants.

The Mongoose name was presumably chosen to strike out at Ford’s current 6.7-liter Power Stroke. Blue Oval dubbed its V8 diesel the “Scorpion,” allegedly because the exhaust manifold and turbocharger emerge from the center of the engine in a “hot-v” configuration. If you use your imagination, it kind of makes the motor look like it has a raised tail. Scorpion is also probably a more marketable name than something like tadpole.

Apparently Mongooses (not Mongeese, for some reason) also eat scorpions, which General Motors made sure to feature in the teaser video. It’s ultimately meaningless bravado. But there are vehicle models and entire car brands that have thrived on little else.

While General Motors withheld any useful information about the motor, we can hopefully assume the company wouldn’t dare field a much larger diesel and then allude to it savagely devouring Ford’s HD entrant without the unit offering improved specs. At a minimum, the Mongoose should trump the 475 horsepower and 1,050 lb-ft of torque available on the basic Ford Powerstroke.

However, Ford’s 6.7-liter can be had with 500 hp and 1,200 lb-ft of torque in select configurations. Considering that GM’s motor is a whopping 8.3-liters, it seems reasonable that those specs should be the true benchmark for the forthcoming powertrain. The question is whether the automaker will aim lower in a bid to maximize under-stressed dependability or chase numbers in the hopes of embarrassing rivals on paper.

Despite not being the typical truck person, I’ve driven the last batch of Ford Super Duty models and it’s honestly hard to imagine someone needing more power. Even when lugging around their maximum trailer weight, they remain extremely compliant pickups. This is likewise true of GM’s current roster of HD models. Sadly, I haven’t towed anything using any of the current Cummins-equipped models from Ram. But it’s all pretty close when you compare the spec sheets.

As much as I gripe about modern automotive technology, trucks have benefited immensely in terms of towing/payload capabilities and the ease at which that can all be managed from the driver’s seat. That’s not to suggest that you’re automatically getting a better truck than you did twenty ago, just that it’s a lot less trouble to tow something today than it used to be.

One supposes that the 8.3-liter Mongoose probably won’t even be able to display its full might until it’s been equipped to gooseneck trucks featuring a ball hitch that would allow it to haul the kind of weight that would otherwise be impossible. Maybe that also played into the Mongoose name.

Otherwise, you’re just getting a huge diesel which will presumably offer a sizable uptick in available power. That’s useful for National Hot Rod Diesel Association (NHRDA) events or for anybody planning to compete in a truck and tractor pull. But the latter group will still probably want to splurge on gooseneck models.

Regardless, we’re still very curious to see what GM will be offering. It looks like the new 8.3-liter will be replacing the current Duramax 6.6-liter V8 entirely. With emissions rules recently having softened inside the United States, we may be entering into another period where domestic automakers chase displacement in an effort to embarrass each other and drive sales.

It’ll be interesting to see the public response with fuel prices having crept up dramatically this year. Granted, the majority of these HD trucks will presumably land inside commercial fleets instead of residential driveways. But businesses likewise care about overhead and returning significantly worse fuel economy might not go over well.

With the Mongoose supposedly planned to debut on the 2027 GMC Sierra HD and Chevrolet Silverado HD, General Motors is going to have to issue specifications for the engine relatively soon. The same goes for showing us photos of things other than sand and weasels.

Expect a follow-up article in the coming weeks.

[Images: General Motors]

Become a TTAC insider. Get the latest news, features, TTAC takes, and everything else that gets to the truth about cars first by subscribing to our newsletter.