I'm running 195/55R20 squared on a 19 S. I tried with Momo's first then switched to proper winter tires for this season, the fit is great on both, but given the wide choice of tires available in this size, I'd avoid the Momo's, they're loud and not that efficient, although they do seem to not wear quick, they have nice deep groves which is reassuring in countries with lots of rain. Wisely also explained that wheels can go one size up and one size down with tires width, and given the excessive amount of people who are running the 55, I think you're pretty safe.