By far the biggest mystery surrounding the hotly anticipated Corvette ZR1 is the type of engine Chevrolet's engineers intend to install. In late October, an eagle-eyed person with access to the GM Parts Catalogue stumbled upon an LT7 listed as a turbocharged eight-cylinder mill with a 5.5-litre displacement. Well, that's no longer the case because the database has been updated to show an entirely different LT7, one that GM had back in the 1980s.

Discovered by a member of the Corvette Forum, the LT7 now appears as a 4.3-litre V6 diesel. Coincidentally, or perhaps not, there was an oil-burner with this displacement between the 1982 to 1985 model years. Engineered for front-wheel-drive cars, this diesel enabled the 1983 Oldsmobile Cutlass Ciera to return 28 miles per gallon in the city and 41 mpg on the highway for a combined 33 mpg. It was also offered in the Buick Century, Chevrolet Celebrity, and the Pontiac 6000 during the same model years.

However, we'd reckon 85 bhp and 165 pound-feet of torque wouldn't be enough for the Corvette ZR1. But why is the Corvette now listed as having a diesel V6 instead of a gas V8? Well, to show GM has a sense of humour is one logical explanation. The cat is probably out of the bag anyway, so why not do some damage control by replacing the true identity of the new LT7 and have fun along the way?

Many would argue a diesel has no place in a mid-engine supercar, although Audi would beg to differ with its R8 V12 TDI concept. A diesel would make more sense in the long-rumoured Corvette SUV but in the age of electrification, a high-riding 'Vette would have a petrol engine assisted by an electric motor to deliver the necessary low-end torque.

Diesel engines have largely fallen out of favour anyway in the wake of the Volkswagen Group's messy Dieselgate scandal. There are more chances of seeing the rumoured twin-turbo hybrid Zora than a diesel Corvette, which would surely upset purists more than the E-Ray or the already confirmed fully electric model.

Gallery: Chevrolet Corvette ZR1 Nurburgring New Spy Photos

Source: Automedia