I use Mobil 1 0W-40. It works for my '13 S550, but check your manual first!

Consider Mobil1 0W-40; meets MB 229.5 spec. Watch for shear-down; UOAs are your friend.

Hey! For a 2012 S550, don't overthink it. I've tried many over the years. Mobil 1's good, but honestly, a quality synthetic like SuperTech from Walmart works great and saves a ton. Just stick to the recommended weight (check your manual!), and change it regularly. You'll be fine. Why spend a fortune?

Hey! For me, safety's key. I use Castrol Edge, around $50. It's not the cheapest, but protects the engine well, which is safer in the long run, right? Happy with it, no complaints after 2 years. Anyone else prioritize long-term engine safety?

Pennzoil's great. Seeing it around $30 online, works well in my '13 S550, no complaints.