how much heavier are the 18's from hte LTZ's?? I have the 17's with covers. I'm just worried that the extra weight would mess with my little ecotec :rolleyes:

btw how wide are both of these wheels?? :confused:

Why would the 18s mess with your Ecotec? The LTZ comes standard witht the Ecotoec. Many including myself have that combo with no problems.