Back when GM’s then-future HF V6 engine family first became public knowledge (circa 2000), a twin-turbo 3.6-liter capable of 360 horsepower was part of the plan. Then Bob Lutz put a 400-horsepower 6.0-liter V8 in the 2004 CTS-V instead. The second generation CTS-V got a 556-horsepower supercharged 6.2-liter V8, opening up a huge gap in the line as the next… More →