Awesome mp81. I assumed a CAI wouldnt do anything, since it basically increases HP, but not MPG. A SRI would grab even more hot air, so it defeats the purpose, lol.
I know a catback system will increase it by 1/2 mpg, but its very helpful into hitting that 40mpg HWY and not at a constant 55MPH. Thats why I was thinking of that 2.4L header/downpipe combo with a GMPP Touring catback. That will do the trick, I hope...
2009 Cobalt LS XFE U74
Mods: K&N Typhoon Intake, Option Cat-Back Exhaust, Cosmo Short shifter, Maxxim Ahead 17X7's, MPx shorty antenna, FE5 Strut/shocks, Tein S Techs, Moog endlinks, Moog spring seaters, ZZP shorty header, LSJ downpipe, LNF front grille