anybody know how bad my mileage would be affected if I was to add the side rails and cross bars then put the black square cargo bag on top that Chevy makes? The bag would just be for a few long road trips. I really dont want to pay to drive our suburban down to San Diego if I don't have to. (10.5mpg) ouch I Figure that it would cost me the same to put the side rails on as it would to drive that thirsty thing down but I at least get to add some CHROME lol (I think the side rails look killer)

 

The hit you'll take on the mileage won't even come close to 10.5mpg. I'd say go for it. The only problem might be adding the side rails though.

 

Just did a road trip last week with a roof bag. I had the avg mpg display on the whole time and didn't notice a dime's worth of difference.

 

sweet jeff thats what I wnted to hear I wasnt sure how the boxy bag thing would hurt the 4 cyl you know the wind drag But i guess its just another box on a box lol