burgundy), and faux wood panelling. The only special edition Manta ever produced for the US market was the "Blue Max", in 1973. This amounted to a blue 1973 Luxus model, with a unique dark blue vinyl roof, mechanical sunroof, and automatic transmission. As emissions regulations were introduced, the Manta's engine was gradually becoming detuned. In the U.S.(1971 - 74) the 1.9 liter cam in head produced only from a low 7.2 to 1 compression ratio. Sales were dropping as the car's performance no longer matched its looks, nor its price. As a project Car & Driver magazine added a turbocharger which effectively boosted the low compression ratio. For the 1975 model year, all Manta and 1900 models were equipped with Bosch L-Jetronic fuel injection systems in the United States due to emission regulations. Yet in Europe, this feature was only available on the high-end GT/E models, which also sported fog lamps and lower front spoilers, which were not offered on any of the US-spec Manta models. Also, the 1974–75 Manta models had large aluminium bumpers to comply with US crash standards of the time; European Mantas did not receive the large bumpers. With the Deutsche mark becoming stronger, and with other costs also rising, US imports of Opels ended in 1975. Instead, the Isuzu Gemini version of the T-car was imported from Japan and sold by Buick dealers as the "Opel by Isuzu", and later, "Buick Opel". The "Opel" name was last used in the US in 1979. Turbomanta The Turbomanta is the rarer of the two special Mantas which entered limited production. Production was a total of 33 cars, with five of them being prototypes and the ones used for public relations. The Turbomanta was actually a 1973 SR with a 1.9-litre "S" spec engine, originally putting out . The British company Broadspeed was chosen to build the turbo cars, and eventually started building five left-hand drive cars for the German Opel AG. These cars were meant only as prototypes. Broadspeed came up with a somewhat special solution, and used a combination of a Holset 3LDG turbocharger, and a carburettor mounted inside a big plenum chamber. The engine itself was fitted with a thicker copper head gasket, and as such the compression ratio was lowered to 7.6:1. The outcome was a 1.9-litre engine which generated , with acceleration from 0–60 mph (97 km/h) in 7.6 seconds. All five cars