Is need to change engine oil in my car in next week. Now the engine is filled with Shell Helix Ultra 1 5W40. I intend to switch into 0W40 again (according to M-B specification: 229.3 and 229.5). It will be Motul 8100 X-max 0W40. What do you fink about switch from 5W40 to 0W40? And about the engine oil type 8100 X-max manufactured by Motul?