air intake plus exhaust gas miles advantage

Basically, air intake allows your car to breathe easier and the exhaust allows it to exhale easier. The reduced stress on the vehicle allows it to function "easier" which will increase gas mileage. The increase may not be substantial but it will be there.

I added a Volant air intake to a 2005 with a 3.5L 5 cylinder and ended up taking it off b/c the engine would bog out when reached 4500 rpm if accelarating quickly, made no difference in mpg. Switched to an aem dry- flow filter in the stock airbox and I always use 93 octane, the engine revs freely to redline. Have not messed with exhaust nor reprogrammed the cpu which may help with big air intake... supposedly the cpu will adjust the a/f ratio even with bigger air intake and/or exhaust so reprogramming may be best bet to find increased mpg.

AEM dry flow filter, not aem

AFE dry flow - no oiling, not aem

try pcmforless.net for more HP ...ask them about a tune and adding air/exhaust mod before if you want better mpg