Actually, who's to say the engine won't be a vr6? But I personally think that a i4 or v6 based off of an existing Ibishu engine is more likely, considering the development cost of a totally new engine, it would make no sense for Ibishu to develop a vr engine just for mr. Turbo. The Peugeot T16 had a modified engine based off of an existing i4 engine, and I believe the same is true for other examples mentioned (Metro, Lancia, Renault etc.).