Previously, General Motors used the G-body designation for unrelated mid-sized cars.
The G-body was based on Cadillac's K-body architecture. The platform was introduced in 1995 with Buick Riviera 2-door coupe (which moved up from the GM E platform) and the Oldsmobile Aurora 4-door sedan (a new model that replaced the Riviera-derived Toronado). By the turn of the millennium, full-sized cars from four different GM makes were using some derivative of the platform.
Platform consolidation
Starting with the 1997 Buick Park Avenue, GM consolidated its four large-car platforms; C platform, K platform, H platform, and G platform; all to the G platform. However, GM decided to retain their previous platform designations.[2] These legacy platform designations were used in the VIN number and official GM publications. Models designated as "G" went out of production for MY (Model Year) 1999, but successor models were sold until MY 2011.
The G-body was noted for having one of the strongest unibody car frames in production (25 Hz). GM literature noted the need to use a 'frame crusher,' designed to test heavy-duty truck frames, to finally break the G-body structure in their crush-to-failure procedures.
The G platform vehicles were also noted for having belt-in-seat style seat belts like the mid-size GMT360 SUVs. [citation needed] The G-body also featured four-wheel independent suspension with a MacPherson strut style front suspension and a semi-trailing arm style rear suspension that utilized aluminum control arms. All-new aluminum control arms were introduced for the front suspension for 1998. [citation needed] The handling was further enhanced with standard front and rear stabilizer bars and lateral links in the rear suspension to further control wheel toe. [citation needed]
* Official designation given by GM, despite using a G platform-derivative. This name also corresponds to the 4th letter in the VIN of the vehicle.
2006 Revision
The G platform was updated for the 2006 model year.[3] The final car using this platform was the Buick Lucerne, which ended production in June 2011.[4]