I'd say that mine is probably the roughest daily driven 535i on the forum. And i don't even get that. 100% city driving and pedal happy? Sounds like It's ready for a tune up. Mine is also a auto, 168k and I'll pull in high 19s for average mpg. 15 if I have fun. If i were you i would get another head, port it, chip, maybe injectors, find a beefy cam, and full exhaust. You would get the better mileage as well as a bit of power. Could put it all in with a headgasket in a weekend. As for the rims. I like the black. I'm sure Chrome looks good. But these cars look great with black accents. Regardless of color.
2003 GMC Sierra SLT 2500HD CC/SB