I want an air filter to filter the dirt and cr*p out of my air, not let it breathe on in all filthy and through my motor. If any of these K&N filters made more power, K&N would be showing dyno runs, side by side, stock and K&N, in their advertisement, to prove their point.
They can't, and they don't... there's your sign. Anything turbocharged and diesel sucks more air with a stock air filter, that an aftermarket unit is a non issue. Motor manufacturers know what's good for their motors, and what makes a motor last... false promises of more power don't do any motor any good.