When I had my 1000k service done (AN650K4) the mechanic put 20/50 weight Dino oil in both the engine and trans. The manual recomends 10/40 weight. When I phoned him about it (the shop is 100km from where I live) he said it was because of all the hot weather we've been having. Since then the clutch engagement is very rough. Anyone else have this problem? Does anyone else use 20/50 Dino oil?