LS6

LS6 is a high-performance variant of General Motors' small-block V8 engine family, part of the GM LS engine lineup. It is based on the LS1 design but features a higher compression ratio, revised rectangular-port cylinder heads, a stronger bottom end, and a performance-tuned cam and intake. It was produced from 2001 to 2004 in the Chevrolet Corvette Z06 (C5) and during 2004–2005 in the Cadillac CTS-V.

The LS6 displaces 5.7 liters (346 cubic inches) and shares the basic architecture of the LS1 while incorporating technical upgrades intended to improve high-end power and breathing. Power output varied by application and year: early Corvette Z06s were rated at 385 horsepower, with later versions rated up to 405 hp, and torque generally in the range of 385–400 lb-ft. The engine is commonly paired with a six-speed manual transmission in the Z06.

In addition to the Corvette, the LS6 was used in the first-generation Cadillac CTS-V, where it delivered comparable performance. In GM’s lineup progression, the LS6 was eventually superseded by the larger-displacement LS2, which appeared in later generations of GM performance vehicles.

The LS6 is remembered for delivering higher-revving, high-performance characteristics within the LS family and for helping establish GM’s performance-oriented approach in the early 2000s. It remains a notable example of GM’s use of refined small-block architecture to achieve substantial horsepower gains in a relatively compact V8.