General Motors W platform

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The W-platform (also known as the W-body) was a General Motors automobile platform which underpinned both mid size and full-size front-wheel drive cars. Originally code named GM10, it began development in 1982 under Chairman Roger B. Smith and debuted in 1987 with the Pontiac Grand Prix, Buick Regal, and Oldsmobile Cutlass Supreme coupés. The four-door sedan version was introduced for 1990.

W-body = wide body
White Pontiac Grand Prix.jpg
ManufacturerGeneral Motors
Also calledGM10
Body and chassis
LayoutFF layout
Body style(s)
VehiclesBuick Century
Buick LaCrosse
Buick Regal
Chevrolet Impala
Chevrolet Impala Limited
Chevrolet Lumina
Chevrolet Monte Carlo
Oldsmobile Cutlass Supreme
Oldsmobile Intrigue
Pontiac Grand Prix
Engine(s)122 I4
Iron Duke I4
Quad-4 I4
60° V6
Shortstar V6
High Value V6
High Feature V6
Buick V6
LS4 V8
Transmission(s)3-speed 3T40 automatic
4-speed 4T60 automatic
4-speed 4T60-HD automatic
4-speed 4T65 automatic
4-speed 4T60-E automatic
4-speed 4T65-E automatic
4-speed 4T65E-HD automatic
5-speed Getrag 282 manual
5-speed Getrag 284 Manual
6-speed 6T70 automatic
  • 107.5 in (2,730 mm)
  • 109.0 in (2,769 mm)
  • 110.5 in (2,807 mm)

Starting with the 2nd Gen 110.5 in wheelbase in 1996 it became a full-size platform as well as a 109 in wheelbase mid-size; from 2005 on the 3rd gen 110.5 in wheelbase full-size was the only version through its discontinuation in 2016.


The platform cost $7 billion to develop and was to replace all midsize cars produced by Chevrolet, Pontiac, Oldsmobile, and Buick on the G and A platforms. This ultimately did not happen; while the A-platform Chevrolet Celebrity and Pontiac 6000 were quickly discontinued, the A-body Buick Century and Oldsmobile Cutlass Ciera remained in production until 1996. The engineering work was done by the Chevrolet-Pontiac-Canada (CPC) group; also known as the small car division.

The plan was for seven GM plants that would each assemble 250,000 of the cars, or 21% of the total U.S. car market.[1] It was badly executed from the start, but GM's 1984 reorganization, combined with changing market dynamics, wrought havoc with the program and it never recovered. By 1989, the year before the last of the original GM10's were launched, GM was losing $2000 on every car it produced.[2]

1996 Buick Regal with Transverse leaf spring rear suspension

The later revision of this platform was known as the MS2000 or simply the W2-Car. Early versions used a transversely installed, fiberglass mono-leaf spring combined with struts in the rear. The "generation 1.5" W-body models had updated rear suspensions that used coil springs instead of the transverse leaf spring design inspired by the Chevrolet Corvette. For the 1997 model year the second generation W-body was released with a MacPherson strut coil spring design.

The W platform was updated in 2004 rather than being replaced by a stretched Epsilon platform, as had been planned. Metal fabrication of the floor pan for W-body cars was performed at the Parma Metal Center in Parma, Ohio. The cars were built at GM's Oshawa Car Assembly. The transverse use of GM's LS small-block engine in the W-bodies was a major addition for 2005.

The GM W Platform was phased out with the production of the new long-wheelbase Epsilon II platform. The last car produced on the W platform was the ninth generation of the Chevrolet Impala, which was replaced by the Epsilon-based tenth-generation Impala, beginning in model year 2014. GM continued to produce the W-body Impala to fleet customers only under the name Impala Limited until production ended in May 2016.[3]


Vehicles using the W-body include:


  1. ^ Taylor III, Alex; Erdman, Andrew; Martin, Justin; Welsh, Tricia (November 16, 1992). "U.S. Cars Come Back". Retrieved 26 January 2018.
  2. ^ Monks, Robert A.G. "GM Corporate Governance Case Study". Archived from the original on November 5, 2008. Retrieved January 26, 2008.
  3. ^ "Impala Limited Fleet Special Lives On To At Least 2016, Keeps Oshawa Open". October 28, 2013. Retrieved January 26, 2008.
  4. ^ "Outgoing Chevy Impala lives another year, as fleet-only model". Retrieved March 13, 2013.
  5. ^ "Outgoing Impala to Continue as 2014 Chevrolet Impala Limited for Fleets". Motor Trend. Retrieved March 13, 2013.