Performance Mods and Gas Mileage
It seems to me that there are a lot of questions regarding the increase/decrease of gas mileage for a particular mod, and I have one of my own. Please help comment if you can.
I installed the Mopar performance CAI and exhaust on my XK (5.7L) and THOUGHT that I was getting better gas mileage, but it turns out, it actually decreased by 1 mpg to an average of 12.5 mpg. (mostly city). I just had my 30k service thinking that new sparkplugs would probably help, but it didn't. I did the reset thing with disconnecting the battery and turning the key to on for 1 min and I really didn't notice anything as far as that goes.
Performance wise, noticeable difference. Quicker off the line, sounds REALLY cool, (except for the throttle body whine) and more reactive. Probably around a 20 hp gain.
Long story short, if you want BETTER gas mileage, I don't think anyone in here has figured out how to do that with a modification, I mean its a 345 CI engine moving around a 6000 lb car, how good of gas mileage do you expect it to get?