GM Theta platform

GM Theta platform

Manufacturer	General Motors
Production	2002–present
Class	Compact/mid-size crossover SUV
Vehicles	Cadillac SRX Chevrolet Captiva Chevrolet Equinox Daewoo Winstorm Pontiac Torrent Saturn Vue Suzuki XL7 GMC Terrain Saab 9-4X

Theta is General Motors' compact and mid-size crossover SUV automobile platform. The architecture debuted in 2002 with the Saturn Vue (Theta, compact crossover SUV) and was later used for the Chevrolet Equinox (Extended Theta, mid-size crossover SUV). The platform was developed by GM in North America, based on the GM Epsilon platform, the same platform that makes the Chevrolet Malibu, Pontiac G6, Saturn L-Series (Later Saturn Aura), and Opel Vectra. The Saturn was engineered in Michigan and the Equinox/Torrent were engineered by GM's Canadian Regional Engineering Center (CREC) in Oshawa, Ontario. Neither Suzuki nor GM's Shanghai, China operation, Pan-Asia Technical Automotive Center has had involvement in engineering or developing the Theta platform.^{[citation needed]}

Development

The Theta uses a four wheel independent suspension. Engine choices include the Ecotec Family II straight-4, 3400 V6, and even a Honda V6, the L66. A 5-speed automatic and two 5-speed manual transmissions are used.

The original Saturn Vue used a short 106.6 in (2708 mm) wheelbase, with a 61 in (1549 mm) track. The Chevrolet Equinox and Pontiac Torrent use a stretched 112.5 in (2857 mm) wheelbase, but shares much with the Saturn.

The Suzuki Grand Vitara, although similar in size and appearance to a Saturn Vue, was developed by Suzuki using some Theta components, but should not be considered a Theta derivative. The Grand Vitara front and rear suspensions are substantially different from the Theta vehicles. The 2007 Suzuki XL7 is based on the Theta platform and is built alongside the Equinox and Torrent at CAMI Automotive in Ingersoll, Ontario, Canada. It is the first non-GM branded vehicle to come off the Theta platform. Styled by Suzuki, the engineering was performed by GM engineers in the US and Canada.

Engineering for the Opel Antara, Chevrolet Captiva, and the Saturn Vue was performed in large part in Korea by GM Daewoo Auto & Technology.

Hybrids

The Saturn Vue was one of the first of General Motors' vehicles to be offered with a hybrid powertrain, GM's belt alternator starter (BAS) system, in 2006. The company also plans to add hybrid versions of the Chevrolet Captiva and Vauxhall/Opel Antara, but those will use GM's Two-Mode Hybrid system instead of the BAS.

Vehicles

Previous Theta vehicles:

• Short wheelbase
  • 2002 Saturn Vue

• Long wheelbase
  • 2005 Chevrolet Equinox
  • 2006 Pontiac Torrent
  • 2007 Suzuki XL7

Current Theta vehicles:

• Short wheelbase
  • 2006 Daewoo Winstorm/Chevrolet Captiva/Holden Captiva
  • 2007 Opel Antara
  • 2008 Saturn Vue

• Long wheelbase
  • 2010 Chevrolet Equinox
  • 2010 GMC Terrain

Concepts

• Chevrolet S3X/T2X

Theta Premium

2010 Cadillac SRX

General Motors has created a premium version of Theta for luxury applications. Reports differ, but the general consensus is that it is a combination of the current Theta and elements of the new Epsilon 2 architecture, with some Lambda components as well. Thus this platform is sometimes also referred to as Theta-Epsilon. Theta Premium supports larger models than the standard platform.

Vehicles using Theta Premium:

• 2010 Cadillac SRX

Future vehicles to use Theta Premium:

• Saab 9-4X

References