heavy rims vs light rims
 

rim an tire now 55lbs 18's looking to go 16's rim an tire 37lbs will i notice difference whp etc mpg or just waste of $$$

I feel a difference when I put my heavy summer wheels and tires on, yes.

stay with the light weight rims all around

you won't notice that much of a difference if it is just for DD

This.

Around the track/canyons, yes, you will feel the difference (rotating mass is where you want to remove as much weight as possible), but on the street?not really.

i noticed the weight of the trd 18s i had on my xA

Its called unsprung weight. And YES it does affect your mpg. I had some wide 17s and noticed that I lost almost 30miles/tank.