No one in the USA cares about fuel economy. Everyone wants trucks and SUVs. The first version of the engine is a 2.0 that's good in the smaller vehicles, and Mazda was supposedly working on a 3.0 turbocharged inline-6 for a new RWD version of the 6, and a new SUV based on that. Recent talk is that the RWD cars are basically canceled because reasons that don't really make sense.