MOTOR SL350 R230 vs. R231

Hello, I have been thinking about putting a Sl in my garage for a long time instead of a BMW 6er. I want to cruize 90% with the car rather than flip around the corners. I drove the SL350 with 315 hp before a few Montaen times, and the engine seems not to be sooooo suitable for it. The car has good power, but only if you turn the engine properly. But that’s not my driving style. The E400 Cabrio goes to the point quite differently. The engine would also fit well with the SL. I think the Sl500 is a bit too oversized for me, because the running costs seem a bit too heavy. I would like to comment on the R231 SL350 engine. Is the engine slightly weak on the chest even in the lower speed range like the R230 ?? Is the engine in the R231 actually a slightly modified R230 engine? Finally I would have a question about the Young Stars warranty. If I Buying a car, e.g. 1 year old with young stars warranty, do I have 2 years warranty or 3 years from purchase? Does the young stars warranty run from the end of the factory warranty, or immediately from purchase parallel to the factory warranty? Thank you, and greeting from the pot.