We already knew that Audi was moving the S4 and the S5 from V8 engines to smaller, lighter turbo V6 units. But now Car and Driver is reporting that the V6s are just a stairstep on the way to reducing the cylinders by half.

This does make sense. Audis have become a little portly in their pursuits for horsepower. For example, the 2010 S5 Cabriolet weighs in at 4300, which is about as much as a Ford Explorer.

Audi acknowledges that this weight disadvantage could really hurt it in the future, and is now taking great steps to fix it. When the new S4/S5 appears in 2014, it will incorporate more aluminum, magnesium, and high-strength steel for weight reduction. It will also switch to turbocharged four-cylinder engines. The result will be a car that has 20 percent less weight and up to 30 percent less engine displacement.

While we're usually not fan of smaller engines, Audi does seem to have a good guide to follow. The current TT lineup doesn't have to cross into six-cylinder territory to get 340 hp with the TT RS.

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