My manuals, I got two versions( manuals for 2003 Rosso Corsa, Nero Corsa, Sport, Cafe Sport, Coppa Italia, Ballabio-Scura R is not mentioned, they probably never made a manual with Scura R written in it) tell me to use 5w-40.
Other manuals for earlier( pre 2003) v11 I read on internet say 20w-50, same as for my 2001 jackal. The jackal manual also gave other options like 10w-40,10w-50,10w-60,15w-50, for different temperatures. I understand Sahara can use a thicker oil than Norway.
So, it`s possible the different recommendations is a coincident?