LQ4 Vs. LQ9: What's The Difference Between These Engines And Where Were They Made?

General Motors introduced the third-generation small-block V8 engine, the 5.7-liter LS1, in conjunction with the new C5 Chevrolet Corvette in 1997. That launch marked the beginning of the LS engine platform that would power GM cars and trucks for more than a decade while maintaining the architecture of the original small-block Chevy engine it replaced.

Starting in 1999, heavy duty pickup trucks and large SUVs from Chevrolet and GMC would get a new LS-based engine, the LQ4. The 6.0-liter LQ4, commonly known as the Vortec 6000, was a version of the LS1 but used cast iron for its engine block instead of cast aluminum.

Purpose-built as a truck engine, LQ4 horsepower ranged between 300 and 330 with torque in the 360 to 370 lb-ft range over its nine years of service, ending in 2007. Improving upon the LQ4, the LQ9, marketed as the Vortec HO 6000 or Vortec Max, also featured cast iron engine block construction and displaced 6.0-liters.

The LQ9 featured higher performance components to make 345 horsepower and 380 lb-ft of torque. GM used the LQ9 in premium large SUVs and pickup trucks from 2002 to 2007, when other GM 6.0L engine versions replaced both LQ engines.

Prior to the financial crisis that hit U.S. automakers and the economy in general in the late 2000s, GM had manufacturing subsidiaries around the world.

Two notable Vortec engine manufacturing plants prior to GM's restructuring were located in Silao, Mexico, and Romulus, Michigan. [Featured image by Spanish Coches via Wikime.