In the complex world of auto manufacturing, it’s not uncommon for OEMs to share parts and collaborate in expensive manufacturing efforts. Such was the case for GM and Isuzu, with the two companies previously involved in the production of the 6.6L V8 Duramax engine. However, these days, the 6.6L V8 Duramax engine is solely a GM effort.
The collaborative effort between GM and Isuzu goes back to the late ’90s, when GM tapped Isuzu as a means of revitalizing its diesel powerplant lineup for use in various GM heavy-duty trucks, among other things. At the time, GM’s diesel market share was dwindling, prompting a partnership that led to the formation of DMAX Ltd., a joint venture with a 60:40 ownership split between GM and Isuzu, headquartered in Moraine, Ohio.
The collaboration resulted in the introduction of the 6.6L Duramax LB7 engine in 2001, which debuted in the Chevy Silverado HD and GMC Sierra HD pickups. The LB7 would undergo a series of updates and changes over the years, eventually evolving into the 6.6L V8 L5P found in GM’s current heavy-duty diesel truck lineup.
In 2019, GM and Isuzu announced a $175 million investment to build a new diesel engine components plant in Brookville, Ohio, aiming to expand production capacity for the Duramax engines. However, by May 2022, GM had acquired full ownership of DMAX Ltd., making it a wholly owned subsidiary and marking the end of Isuzu’s direct involvement in the joint venture.
These days, the DMAX Ltd. production facility in Moraine continues to manufacture the 6.6L V8 L5P for use in the Chevy Silverado HD and GMC Sierra HD, as well as the 6.6L V8 L5D engine for use in the Chevy Silverado MD lineup (4500 HD, 5500 HD, and 6500 HD). In addition, the facility also produces engines for use in various military and marine applications.
Meanwhile, Isuzu currently doesn’t offer the Duramax 6.6L V8 in any of its trucks or commercial vehicles, further underlining the division between GM and Isuzu when it comes to this particular powerplant. In fact, the Isuzu F-Series and Chevy LCF 6500 XD / 7500 XD, which are essentially the same truck with different badges, are all equipped with a Cummins-sourced 6.7L engine, rather than a GM engine.
On the topic, we could also mention that the Chevy Silverado HD and GMC Sierra HD are equipped with an Allison-branded 10-speed automatic transmission that isn’t really a “true” Allison, but rather, branded as an Allison transmission while designed and built in-house by GM. But that’s a discussion for a different day.
Comments
Another bad decision by Mary.
Isuzu was removed way before Barra.
Tell me you didn’t read the article without telling me you didn’t read the article. Do not pass go, do not collect $100.
“However, by May 2022, GM had acquired full ownership of DMAX Ltd., making it a wholly owned subsidiary and marking the end of Isuzu’s direct involvement in the joint venture.”
She’s been on the job over a decade!
kool-aid drinker
Since Isuzu is out of the picture being that they manufacture more diesels engines than any other manufacture I wonder about if the learned quality will stay. Just pondering.
GM pioneered engineering-out quality, even if they acquired proven designs from other manufacturers. Now, simple deductive reasoning provides clear answers.
Mary and quality don’t go together.
So. I this to say that since 2022 the 6.6L DMAX has a 10 speed traditional transmission? The transmission GM is having trouble with?
2020 new body, and yes
Isuzu hasn’t really had any direct involvement since like LLY or LBZ.
The original agreement was they’d help build the LB7 and then it was up to GM to take it from there and the Isuzu ownership would dilute over the course of like 25 years or something. Had the agreement matured fully Isuzu would have lost their ownership stake eventually anyways, the 170 million deal just accelerated it a tad and kicked Isuzu out a few years early
GM was never good at building light duty diesel engines. I can totally see end of Duramax coming.
My early 2007 has over 500k runs like a top.
I miss Joe Isuzu.