Finally made the move after much deliberation. These dropped over 2LBS per wheel vs. OEM while adding 1" diameter and 30mm wider tires.
I had Dunlop Direzza ZII 215/45/17 and replaced with Michelin Pilot Super Sport 245/35/18. This maintained nearly identical wheel size and avoided any need to adjust the speedometer, a plus. Also no rubbing problems whatsoever although clearance in the front to my new Eibach Pro lowering springs is as close as I would dare see.
So a reasonable 1" drop from the springs which provides a nicer look without serious compromise to clearance needed on New Hampshire frost heaved roads.
At the same time I also installed the Raceseng 3 piece Pulley Kit. It was shocking how much lighter these were than the OEM pulleys!
So I shaved like 6lbs off the pulley's and about 9lbs of unsprung tire/wheel weight. The heavier Eibach lowering springs added back a few lbs.
Aside from a new and (IMO) far better look, the car now has significantly better road stick in hard corners and at launch. Firmer suspension that is pleasantly not detectably harsher. And definitely I am noticing a real improvement in acceleration. Mind you I am already running AVO Turbo at 9PSI and a complete exhaust replacement. Last Dyno was 291 RWHP on a Mustang heartbreaker prior to these most recent upgrades.
