Using the 3%-6% mirror contribution to drag, from here:
http://ecomodder.com/forum/showthrea...tified-95.html
And the calculator here:
Aerodynamic & rolling resistance, power & MPG calculator - EcoModder.com
I get a 2-4% improvement in mpg at 45 mph from eliminating the mirrors. Everything else on the calculator I left at default.
Also, later in that first link, Metro saw a 2.3% increase from removing one mirror and folding the other, at 55 mph.