Re: Confused about Tyres for 147 1.6 TS
i'd keep away from a 55 profile, its too soft, so your handling is compromised. 50 is my preffered profile, its thin enough to give you good feedback and predictable cornering but also thick enough to deal with uneven road surfaces and potholes without buckling your wheels or making you uncomfortable.
the difference a 50 profile makes to your speedo is -3.24%, so your speedo will say 70mph when you are really doing 67.73mph, but that assumes your speedo was accurate to start with. since they read 5% over on average then its likely that your speedo would be made more accurate in reality. GPS will confirm the exact change. either way its not a significant change.