Which is better 5w30 or 5w40?
The difference between 5w30 and 5w40 is that 5w40 has larger viscosity than 5w30. This means 5w30 is better than 5w40.
What oil do Mercedes recommend?
Mobil 1 Tri-Synthetic Formula 0w-40. Valvoline Synpower Full Synthetic Motor Oil 5w-40.
What happens if u put wrong oil in car?
Using the wrong fluid can cause poor lubrication, overheating, and possibly transmission failure. A mechanic might not be able to reverse the damage, even by flushing the transmission. Mistakenly adding motor oil or brake fluid can also destroy your transmission.