If you do the rim/tire mods, try for improvements in as many of these categories as possible simultaneously: overall tire/rim weight reduction, aero cover or vent blocking, narrower and taller tire/rim combination, and Low Rolling Resistance tires. It can be done. Takes a lot of research. Checkout our wheel discs showcase thread for ideas:
https://ecomodder.com/forum/showthre...scs-37690.html