GM Sigma platform


Sigma was General Motors' mid-size rear-wheel drive automobile platform. The architecture debuted in 2002 with the 2003 Cadillac CTS and is adaptable for all-wheel drive and extended wheelbase versions.
The long-wheelbase Cadillac STS replaced the front-wheel drive GM G platform Cadillac Seville. The CTS was a replacement for the rear-wheel drive V-body Cadillac Catera.
The Sigma platform has a four-wheel independent suspension with control arms in front and multi-link in the rear. GM's High Feature V6 and Northstar V8 are most common, though the small-block V8 has also been used. GM's 5-speed 5L40/5L50 automatic transmission is used throughout the range.
All Sigma vehicles are built at the purpose-built Lansing Grand River factory in Lansing, Michigan.
Vehicles based on this platform:
The Sigma II platform debuted with the 2008 Cadillac CTS, and is larger and wider than its predecessor. However, it is more flexible; sharing more parts with the larger Zeta platform than it does with the Sigma I platform. Despite this parts sharing, Sigma II remains exclusive to Cadillac vehicles. For the 2011 model year coupé and station wagon body styles were introduced. Engines for this platform range from the High Feature V6 engine to the supercharged LSA V8 in the Cadillac CTS-V.
Applications: