General Motors Proving Grounds
North America 
Desert Proving Ground Yuma 
Desert Proving Ground Yuma is a facility co-built and leased by General Motors located within the US Army's Yuma Proving Grounds. The site contains a inner facility sitting on 2,400 acres with a 24 acre campus containing 98,000 ft2 of building area and also has 40 miles of roadway. One of the main reason that this site was chosen was the already imposed no fly zone which helps prevent unwanted photography of pre-production prototypes undergoing testing. The facility is also used by the US Army for their own testing requirements.
Other such features are:
- 3.5 mile Circle Track (3 lanes)
- 1.4 mile Straight Track (2-3 lanes)
- 3.1 mile Ride Road (2-4 lanes)
- 1,000’ X 1,000’ Dynamics Pad
- Interior Noise Road
- Noise Pass-by Facility
- Misc. Grades
- 72,000 ft2 Main Building
- Garage (40 Hoists)
- Office (120 Residents/Visitors)
- Product Electronics/Instrumentation Lab
- Alignment/Tire Facilities
- Transmission Build Room
- Machine/Fab Shop
- Parts Crib
- Warehouse 14,000 ft2
- Sundrella (40 hoists)
- Covered Parking
- Fuel Facility
- Car Wash
- Scale House / Ballast Station
The facility came fully online as of July 2009.
Milford Proving Ground 
The General Motors Milford Proving Ground was the industry's first dedicated automobile testing facility when it opened in 1924. It is located in Milford, Michigan and covers 4,000 acres (16 km²). 4,800 staff work in its 107 buildings today. The proving ground includes the equivalent of 132 mi (212 km) of roads representative of conditions found on public roadways and other specialty surfaces for vehicle testing. Some roads are open only to drivers who have passed special performance driving training. The saying goes that each mile driven on the grounds is the same as 5 miles (8.0 km) in the real world.
- The VDTA ("Vehicle Dynamics Test Area"), also known as "Black Lake", is a 67-acre (270,000 m2) pad of blacktop for vehicle dynamics testing. Waterfowl have been known to try to land on this "lake" of asphalt. At the ends of the VDTA are two semicircle tracks used for accelerating vehicles up to high speed before entering the pad. A controlled low-friction area made of ceramic tiles is on one side of the pad. Another area is coated with the asphalt sealant Jennite and can be watered down to produce a low friction surface.
- The Oval Track is a 3.8 mi (6.1 km) circuit
- The Circle Track encloses the VDTA and is a 4.5 mi(7.2 km) banked circle. It has five lanes posted with speed limits increasing towards the outermost lane. The speed limit for the outermost lane is 120 MPH (192 km/h). Due to the banking, each lane can be driven at its posted speed all the way around the circle without needing to touch the steering wheel, given proper wheel alignment and tire pressures. The track surface is extremely hard "dolomite" concrete for wear resistance.
- The North/South Straightaway is 6.225 mi (10 km) miles in total length and includes two 2.5 mi (4 km) straightaways
- The East/West Straightaway is 3.1 mi (5 km) miles around and includes two 1.2 mi (1.9 km) straightaways
- "Seven Sisters" is a short course featuring seven tight curves, some level, some banked. It is one lane that can be driven in both directions, so only one car is allowed on the course at a time. This is used for testing vehicles under transient lateral acceleration loads.
- 12 Mile Road is a straight section of pavement which duplicates the historical surface texture of a section of 12 Mile Road near Detroit.
- The Ride and Handling loop encloses the Circle Track and has varied surfaces and turns.
- The Vehicle Safety & Crashworthiness Lab includes a recently added rollover test facility.
Cupuán Proving Ground 
General Motors Proving Ground Cupuan del Rio is situated between Lázaro Cárdenas and Uruapan, Michoacán, Mexico. The facility opened in 2006 and features a circle track, several off-road courses, and is primarily used for testing HVAC systems.
As of 2011 the grounds are mostly abandoned, and only a local security staff remains. This is due to the volatile, potentially unsafe situation in the region and the access routes to/from Cupuán.
South America 
Cruz Alta Proving Ground, Brazil 
- Founded in 1974
- Proving Ground facilities
- It is the largest and most comprehensive proving ground in Latin America, and the second largest in the General Motors Corporation. It comprises the most advanced test tracks, which precisely replicate the most varied and demanding road conditions. 
- GM do Brasil is committed to the preservation of forests and the animal species that live there. Cruz Alta Proving Ground for example, has test roads and tracks that sit amid a forest reserve of 4.6 million square meters, including 2.27 million square meters of reforested trees. The Proving Ground also features 100,000 square meters of Atlantic Forest original vegetation; 10,000 planted fruit trees and more than 1 million square meters of lawns. In addition, GM do Brasil recently partnered with IBAMA, the Brazilian Environment Protection Agency, to monitor the abundant proliferation of capybaras at that location.
Testzentrum Dudenhofen 
Opel operate a proving ground near Dudenhofen, Germany , opened in 1964. Facilities include a 4.8 kilometre high-speed circuit, a 900m section of Belgian pavé and a hill circuit with gradients up to 30%.
Millbrook Proving Ground 
Millbrook Proving Ground is a vehicle testing centre located at Millbrook in Bedfordshire, England. One of the largest vehicle testing centres in Europe, it is near to the M1 motorway and Milton Keynes.
Modelled on the Milford Proving Ground, in Michigan, USA, Millbrook was constructed  in the 1960s by the GM subsidiary Vauxhall. The two mile (3 km) five lane high speed track came into use in 1969, and construction of other sections continued into the early 1970s.
Due to the geographical needs of a full testing centre, including both hills and flat land, the traditional choice of a former RAF airfield was ruled out and many sites around the UK were surveyed before the location at Millbrook was decided upon, especially due to having the benefit of being close to Vauxhall's production site at Luton.
Construction began in 1968 and once opened acted as the testing site for many European GM models from, amongst others, the Vauxhall and Bedford companies. In 1988 the site was transferred to a new company, Millbrook Proving Ground Ltd as part of Group Lotus and began to offer its facilities as well to non-GM companies. With the sale of Lotus in 1993 Millbrook was transferred to GM Holdings UK Ltd as an independently managed company and began to diversify into all aspects of vehicle testing including emission control.
The centre provides vehicle test and development facilities including:
- Vehicle and system assessment
- Powertrain development
- Safety testing.
These are staffed by engineering teams who work with manufacturers on their test and development programmes.
Millbrook has a wide range of types of test tracks. The most prominent are the:
- Hill Route - divided into three sections or loops which contain progressively steeper gradients and tighter corners. Sometimes seen in motoring television programmes, for example Top Gear, particularly the "ski-jump" where it is very easy for vehicles to become airborne. Also used for the James Bond film Casino Royale.
- Outer and Inner Handling (or City Course) circuits - extremely technical twisty circuits used for extreme testing of vehicle handling characteristics.
- High Speed Bowl - a two mile (3 km) circular banked circuit used for higher speed testing.
The proving ground maintains a high standard of security and secrecy to protect the commercial interests of its customers. Public access is not generally permitted and the facility is hidden from view by belts of trees. Limited supervised access to the facilities is available through some driver training organizations.
Millbrook has been the site of many challenges featured in BBC's Top Gear, such as the Non-Porsche Coupé challenge in Series 6 (using the Hill Route, dubbed the "Alpine Circuit" by the presenters), the Convertible People Carrier challenge in Series 8 (using the High Speed bowl), the British Leyland challenge in Series 10 (using the Skid Pan and one of the Handling Circuits) and the "Lorryist" challenge in Series 12 (using the Skid Pan, the Hill Route and the High Speed Bowl).
Lang Lang Proving Ground 
It was opened in 1957 by GM-Holden and has been used to test every Holden model from the Holden FC onwards. It is a dedicated 877-hectare site with 44 kilometres of road systems, including a 4.7 km 4 lane circular track (speed bowl), 5.5 km ride and handling course, a 1.8 km noise road and 98m diameter skid pan. It is also equipped with an Emissions Laboratory and Safety Test Facility with crash barrier and hyge sled.
Guangde County, Anhui, China 
GM opened in 2012 China’s largest proving ground.
Proposed / Closed Proving Grounds Facilities 
Mezcala Proving Ground 
GM's proposed facility at Mezcala, Mexico was terminated in the planning phase due to breakdown in land negotiations. The facility was to take over Desert Proving Ground tasks when GM announced DPG's closing in 2000. DPG is still operating as of late 2008. Soon to be closed and replaced with the new facility in Yuma, Arizona.
Desert (Mesa) Proving Ground 
GM Desert Proving Ground in Mesa, Arizona was a General Motors facility for the testing of HVAC, propulsion, and various automotive systems in a harsh climate. This facility is now closed and was replaced by a new facility in Yuma, Arizona.
- "GMTC - MPG Facts & Figures". General Motors. Archived from the original on 2008-08-04. Retrieved 2008-10-03.
- "Vauxhall Owners' Supplement". Autocar. nbr 3466: pages 1–52. date 23 November 1968.
- GM and Partners Open China’s Largest Proving Ground