Even though General Motors used the term 'show car'

Even though General Motors used the term 'show car' to describe the sporty Buick Regal GS that made its world debut in Detroit, there's nothing conceptual about this model. The GS version of the new 2011 Regal sedan that's due to go on sale this summer is said to be identical to the Opel Insignia OPC in all but one element: the engine.

According to GM, whereas the OPC gets a 2.8-liter twin-scroll turbocharged with 325HP, the all-wheel drive GS is fitted with a tuned up version of the Regal CXL's 2.0-liter turbo four that makes 255HP.

However, if you pay attention to the second promotional video after the jump (pause at 52 seconds into the film), you'll see that the GS features a V6 Turbo...

We don't know if anyone popped up the hood on the Regal GS showcar in Detroit to see if it's fitted with a four-pot or a V6 Turbo, but the best explanation we can give is that GM's team took the OPC, added Buick's logos and waterfall grille along with a pair of bonnet air-vents leaving the Opel's hardware intact.

It remains to be seen whether or not GM will offer a production version of the Regal GS in the States, and if so, if it will be powered by a four-cylinder or a V6 turbo engine. Till then, watch the two videos after the break or click here to read more details about Buick's sporty saloon proposal.

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