The road-going Opel Calibra, introduced in 1989, was styled with a drag coefficient of just 0.26, the lowest of any production car in the world at the time. This aerodynamic efficiency made it an attractive basis for a racing programme. The DTM/ITC-specification race cars departed dramatically from their road-car origins, using an all-wheel-drive layout with the engine mounted longitudinally rather than transversely, as was the case in the road car.
The early DTM cars were powered by a naturally aspirated Cosworth-developed 54-degree V6 engine based on General Motors' iron block and aluminium head C25XE unit. Power output improved from 420 PS to 480 PS between 1993 and 1995 as development work progressed.
Opel entered the Calibra in the DTM at a time when the series was dominated by intense factory-backed competition. The car's aerodynamic shape gave it an inherent advantage on faster circuits, and Opel operated a works programme supplemented by satellite entries from specialist racing outfits including Zakspeed.
Due to significant changes in the Group A Class 1 FIA regulations for 1996, Opel was required to switch its engine specification. The new unit was an all-aluminium, 75-degree Cosworth KF V6 based on the Isuzu 6VD1 engine as used in the Isuzu Trooper and Amigo. This high-revving unit was capable of reaching 15,000 rpm. Using this engine, Opel won the 1996 ITC Championship — the final season of the high-tech touring car formula before the series collapsed under the weight of its own costs.
Drivers associated with the Calibra's DTM and ITC campaigns included Alessandro Nannini, who drove alongside other works pilots as Opel sought to mount sustained title challenges against the dominant Mercedes-Benz 190E and later the C-Class.
The DTM Calibra was a silhouette racing car, sharing only the visual outline of the road-going coupé. Its race-specification body featured purpose-built aerodynamic components and the gull-wing doors were not part of the standard vehicle. Mechanically, the switch to longitudinal engine mounting and full all-wheel drive distinguished it from Opel's front-wheel-drive road cars, and the sequential gearbox, roll cage structure, and Class 1 aerodynamics package placed it firmly in the category of purpose-built prototype touring cars.
The last known KF V6-powered Calibra race car in existence is the Zakspeed Calibra Concept 2 prototype, built as a test mule for the cancelled 1997 FIA ITC championship before the entire programme was shelved following the ITC's dissolution at the end of 1996.
The Calibra's DTM career spanned the period when the series was at its most technically extravagant and financially demanding. The Class 1 formula, which the Calibra competed under from 1996, was so expensive that it drove away the manufacturers and caused the series to fold entirely. When the DTM was revived in 2000, Opel returned with a new iteration of the Astra-based silhouette racer, continuing a lineage that had begun with the Calibra. Special road-going editions of the Calibra, including variants badged with the DTM name and a Keke Rosberg edition, were sold to honour the car's motorsport heritage, their yellow-grey textile interiors referencing the colours of Opel's DTM liveries.