2020 S450- check coolant level warning

It runs great and I love it!!
I had “Check Coolant Level” warning that popped up this morning. I live in Maryland and it has started to get a little cooler and was 35 degrees this morning.
I’ve attached the picture of the warning here.
The warning came at startup this morning and went away. The car temperature has been half way throughout the drive and on my way home this evening and the warning didn’t appear this afternoon when I started it for my trip home.
is it due to weather change to a little cooler or should I add some coolant to the reservoir to be on the safe side? Please share some thoughts.
I just want to buy the right coolant and keep it in the garage just in case for now or the future.
Can you please let me know the right spec for the coolant for 2020 S450 (6 cylinder)?
Thanks much!




There is probably more than just temperature and volume change that is going on. Perhaps your coolant level is just at the minimum design limit. I'd add more and keep an eye on it twice a day.
This is the OEM Mbenz coolant antifreeze:
https://www.fcpeuro.com/products/mer...BoCpdUQAvD_BwE
Last edited by S_W222; Nov 14, 2025 at 06:57 PM.
It runs great and I love it!!
I had “Check Coolant Level” warning that popped up this morning. I live in Maryland and it has started to get a little cooler and was 35 degrees this morning.
I’ve attached the picture of the warning here.
The warning came at startup this morning and went away. The car temperature has been half way throughout the drive and on my way home this evening and the warning didn’t appear this afternoon when I started it for my trip home.
is it due to weather change to a little cooler or should I add some coolant to the reservoir to be on the safe side? Please share some thoughts.
I just want to buy the right coolant and keep it in the garage just in case for now or the future.
Can you please let me know the right spec for the coolant for 2020 S450 (6 cylinder)?
Thanks much!
Since your temp gauge was normal, a small top-off is likely all you need.
For your S450, you must use Mercedes-Benz specific coolant. Get the genuine stuff and mix it 50/50 with distilled water before adding.

https://www.fcpeuro.com/products/mercedes-engine-coolant-antifreeze-genuine-mercedes-mer-q1030005
https://www.fcpeuro.com/products/mer...BoCpdUQAvD_BwE[/QUOTE]






