In the summer of 1986, Vauxhall acquired the cult British sports car company, Lotus, and the motoring world wondered what on earth the maker of the Viva and Cavalier family saloons was going to do with the high performance car maker. They had to wait three years to find out.Take a normal family saloon car and stick a 3.6 litre Lotus Engine in it and what do you get?The Vauxhall Lotus Carlton which in 1990 became the fastest saloon car in the world capable of speeds up to 176 mph.Vauxhall Motors had been owned by US automobile giant General Motors (GM) since 1925 and since 1962 when GM acquired German manufacturer Opel, both companies had regularly shared the same designs, engines, components and cars under different badges for their respective markets.The early Carlton’s were modest relations of what was to come.The first Vauxhall Carlton or Omega as it later became known in Europe and the US, was the British version of the Opel Rekord from Germany.The Mark 1 Carlton was a typical 1.8 or 2.0 litre petrol four door large family car aimed at the middle market to compete with the Ford Cortina and Granada. A spacious and comfortable real wheel drive motor with reasonable performance, it was also available as an estate car.Yet despite many interior design upgrades and a diesel version, sales were not spectacular.The Mark 1 Carlton was mostly built in Germany and assembled at the Vauxhall Luton plant from 1978 until 1986 when it was replaced by the Mark 2, which was to become the basis of the Vauxhall Lotus supercar.The new Carlton was a totally different beast to its predecessor. Designed to take on both Ford and BMW for the British executive saloon market, at the end of its launch year of 1986, the Carlton / Omega range earned itself the industry accolade of European Car of the Year.The Mark 2 Carlton was powered by a straight-6 engine with a 2.6 and 3.0 litre choice. In 1986 the engine had 12-valves, but later models offered a much more powerful 24-valve version in the Carlton GSi which became the basis of the Lotus production car.Although it was unveiled at the 1989 Geneva Motor Show, it wasn’t until 1990 that the Vauxhall Lotus Carlton entered production. Apart from an obvious rear spoiler, low profile body kit and a couple of air intakes under the bonnet, there was little to tell the car apart from the family model. However it was what was under the bonnet that made this the worlds fastest four door production car ever!The 3615 cc V6 Lotus engine was built with a four valve cylinder aluminium head with twin overhead camshafts. Fitted with twin Garrett T25 water-cooled turbochargers the car developed 377 bhp at 5200 rpm, with an incredible 419lb per foot of torque.The drive was taken via a six speed gearbox taken from the GM Chevrolet corvette to a strengthened rear wheel differential. This enabled the Lotus Carlton to reach an amazing speed of 176 mph when tested at the high speed Nardo track in Southern Italy.GM planned producing 1100 cars initially over three years, however due to the recession that hit at that time and the high price tag of £48000, sales were slower than expected and only 950 cars were eventually built when Lotus made the last Carlton in 1992.The Lotus Carlton will probably go down in history as the world’s fastest saloon car that nobody knew about! The fact that the car was so fast caused so much controversy that the corporate advertising of the day did not mention this fact, only that it could accelerate from 0 to 60 in 5.2 seconds! Had they sold the car on its amazing capabilities, the Vauxhall Lotus Carlton may have had a much different story.