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GM's new 8.3L Duramax: what we know so far
GM has announced a bigger Duramax. Here's what's confirmed so far, and what it means for the trucks already on the road.
GM has announced a new 8.3-liter Duramax diesel, nicknamed Mongoose, with a short teaser video. Every Duramax V8 since the first one in 2001 has been 6.6 liters, so this is the first time a pickup Duramax gets bigger.
What's confirmed
GM has confirmed two things: the Duramax name and the 8.3-liter displacement. It hasn't released horsepower or torque figures.
For comparison, the current L5P makes 470 horsepower and 975 lb-ft of torque, according to Hagerty's coverage of the announcement.
What's reported but not official yet
Coverage of the announcement puts the new engine in the 2027 Chevy Silverado HD and GMC Sierra HD. We'll update this when GM publishes specs.
What it means if you own a Duramax now
Nothing changes for your truck. The L5P, the LML and the older engines are all still here, and they still need the same maintenance and the same attention to their known weak spots. The weak spot on each generation is in this list.
A brand-new engine also means nobody has years of experience with its quirks yet. That will come as they get miles on them.
