I switch tire after 1000km with Michelin PSS 205/45/17 stock size on my Lusso. It is much better than original tire. My mods are EC ECU Phase 1. EC V4 intake, GFB+ and GWR exhaust. When I full throttle at 3500 to 4000RPM 1,2,3 also with 4th gear traction kick in. Also switching gears at 6250-6500 RPM 1 to 2, 2 to 3, 3 to 4 same problem, traction kick in. This happens with slippery roads. In my city most of the road surface is slippery. Is it good idea to switch tire to 235/40/17 which is too similar diameter with original tires? Or because of HP and TQ increase I need bigger diameter tire Which can be 225/45/17. I checked mx5 forum some say okey some say it is rubbing for 235/40/17. Also I have only 2 option for this dimension tire Hankook Ventus v12 EVO2 k120 or CONTISPORTCONTACT 5. Which is more grippy?