Who makes Duramax engines?

GM makes Duramax engines, with different production arrangements by engine family.

Owner
General MotorsGeneral MotorsGM owns DMAX after Isuzu stake sale
Company record
Made by
GGMSeparate 6.6-liter L5P and 3.0-liter programs
Company record
Made in
United StatesUSAMoraine L5P and Flint 3.0-liter engine operations
Company record
Illustration of a generic tire, not a photo of Duramax engines.
Exploded illustration of a generic tire1Tread2Belts3Carcass4Beads5Inner liner

SuppliersMap research desk · Source records checked against 4 sources, at least 0 published by General Motors · How we check

Duramax engines supply chain

OwnerGeneral MotorsGeneral Motors
BrandDDuramax engines
Made byGGM
Made inUnited StatesUSA
Key part supplier: Not named by General Motors Not disclosed

Its dated specifications name Moraine, Ohio for the 6.6-liter L5P and Flint, Michigan for the 3.0-liter diesel; the former Isuzu DMAX joint venture ended after Isuzu’s May 2022 stake sale. [1] [2] [3]

Who actually makes Duramax engines?

The 6.6-liter L5P and 3.0-liter Duramax are separately documented GM engine programs. GM’s September 2026 announcement also describes a new 8.3-liter diesel for 2027 HD vehicles; this future program should not replace the maker and plant record for an older engine. [1] [2] [4]

Where is Duramax engines made?

GM’s September 2024 L5P specification lists Moraine, Ohio assembly using globally sourced parts. Its April 2023 release names Flint Engine Operations for the 3.0-liter. The September 2026 release says the new 8.3-liter will be built at expanded DMAX in Brookville, Ohio. [1] [2] [4]

Is Duramax engines made in China or the USA?

US assembly is documented for the specified L5P and 3.0-liter programs. Globally sourced parts do not mean all components are US-made, and these examples do not establish the origin of every historical or international Duramax engine. [1] [2]

Same factory, different label

Chevrolet and GMC use the documented GM engine programs, but displacement, engine code and model year matter. The 2026 HD announcement also includes a 6.6-liter gasoline V8; it must not be confused with a 6.6-liter Duramax diesel. [2] [4]

Where was your tire made?

A company address and a country of manufacture answer different questions. Start with your exact model.

  1. Read both sidewalls for the country-of-origin marking.
  2. Record the complete DOT tire identification number and date code.
  3. Check the specific size and production batch rather than another tire from the same brand.

What each source proves

2024-09

Ppoweredsolutions.gm.com

GM L5P 6.6L Duramax product specifications

GM’s September 2024 L5P specification sheet identifies 6.6-liter Duramax assembly in Moraine, Ohio using globally sourced parts.

Company record2023-04-05

Nnews.gm.com

GM 3.0L Duramax SierraAT4X announcement

GM’s April 5, 2023 release identifies continued 3.0-liter Duramax assembly at Flint Engine Operations, Michigan for the announced Sierra AT4X program. It does not assign all Duramax families to Flint.

Company record2025-03-31 · coverage year

Iisuzu.co.jp

Isuzu fiscal 2025 securities report

Isuzu’s fiscal 2025 report records the May 2022 sale of its remaining 40% DMAX stake to GM and the end of the joint venture. The earlier joint ownership is historical.

Company record2026-09-24

Nnews.gm.com

GM 2027 HD Duramax engine announcement

GM’s September 24, 2026 announcement describes the new 8.3-liter Duramax for 2027 HD vehicles and planned assembly at expanded DMAX in Brookville, Ohio. It is not an allocation record for every existing engine.

Company record

Duramax engines milestones

  1. Isuzu sold its remaining 40% DMAX stake to GM and dissolved the joint venture. [3]
  2. GM’s L5P sheet identified 6.6-liter assembly in Moraine, Ohio. [1]
  3. GM announced the new 2027 HD diesel program and planned Brookville assembly. [4]

Questions people ask

Who owns duramax engines?

GM is the company behind the documented Duramax engine programs. Isuzu’s fiscal 2025 report states that it sold its 40% DMAX stake to GM in May 2022 and dissolved the joint venture; an older GM–Isuzu ownership description should be dated as history. [1] [3] [4]

Where is duramax engine made?

GM’s dated documents identify Moraine, Ohio for the 6.6-liter L5P and Flint, Michigan for the 3.0-liter, using the stated product and reporting scope. Its September 2026 announcement assigns planned 8.3-liter production to expanded DMAX in Brookville, Ohio. [1] [2] [4]

Is duramax engine made by isuzu?

Isuzu helped establish the historical DMAX joint venture, but its fiscal 2025 report says it sold its remaining 40% stake to GM in May 2022 and ended the venture. GM is the company behind the documented Duramax programs; the engine code determines the relevant assembly operation. [1] [2] [3]

Who makes duramax diesel engines?

General Motors is the company behind Duramax diesel engines. The reviewed GM sources separately identify 6.6-liter L5P assembly in Moraine, Ohio and 3.0-liter assembly in Flint, Michigan; Isuzu’s filing records the end of its DMAX joint venture in 2022. [1] [2] [3]

Sources

  1. [1] PGM L5P 6.6L Duramax product specifications2024-09 · company · Source record checked 2026-10-26
  2. [2] NGM 3.0L Duramax SierraAT4X announcement2023-04-05 · company · Source record checked 2026-10-26
  3. [3] IIsuzu fiscal 2025 securities report2025-03-31 · company · Source record checked 2026-10-26
  4. [4] NGM 2027 HD Duramax engine announcement2026-09-24 · company · Source record checked 2026-10-26