I have a 07 GMC Duramax that I was pondering putting an aftermarket intake on to increase performance and maybe squeeze a few more MPG out of it. K&N, Air Raid, Banks, etc.... Do these really work or is it all a marketing campaign? Any recomendations?
Beware K&N (and similar) filters: they filter like shit.
Very true whats bad is most people don't realize a paper filter flows more till it gets clogged up. If I were you I'd go with a chip/programer first by far the best bang for the buck on a Diesel exhaust helps to but being yours is an 07' an exhaust system could affect the regen system on the truck.