Is the expense of a K&N air filter insert justified over the OEM (Mahle) part for my stock 914-6?

Thx,

Skip Montanaro

Nope, not according to the test results I've seen published. The OEM filter and assembly is pretty efficient as it came from the factory.

K&Ns are reusuable. That's the advantage. They claim to add horsepower but so did the "Eram".