ML63 M156 oil level

[Jobsworth]

I’m sure you’re right.

My Dad always fills to max - I think most home mechanics do - and I can’t think of any reporting issues caused by over filling.

I’m a mid way kind of guy.

Answer is, it depends. There are some cars out there, BMW N55 for example, if you want to drive it properly on the track , or even the road if you are spirited with it, you want 0.75L above max, or you’ll likely pick up air in the corners and lunch the engine. The “proper” BMW’s with proper M engines (start with an S) have double pick ups and baffled sumps to make them more suited to track work.
Just an aside to mix it up a bit

 

[E55BOF]

I have no plans to take the ML on the track...

 

[BlackC55]

I’m sure you’re right.

My Dad always fills to max - I think most home mechanics do - and I can’t think of any reporting issues caused by over filling.

I’m a mid way kind of guy.

It can cause issues. When at reasonable temperature 10-15 mins idle (at winter time) 5 mins after switch off if the level is at 3/4 that is perfect. At full operating temp the level will be 1/1. Synthetic oil expansion when hot is more than people realise. In AMG's they hold some serious amounts of oil. Completely dry to completely wet its around 10L of oil.

A Vito with a 642 has around 10L of oil on a change. If you leave the oil at 3/4 at a reasonable oil temp it will be over filled and you will get an oil high warning at max oil temp, usually during a long journey.

 

[ALFAitalia]

Its possible to kill and engine by severely over or under filling....but not by a little bit......You cant have an engine that will self destruct at anything above or below the dipstick limits....so they will build in a decent safety margin on the stick.
But if you go over by too much the crank webs can whisk the oil into a foam so that you end up with an engine full of oil foam and the pump starts to suck up too much air causing starvation at the top of the engine. So you get that odd situation that too MUCH oil causes oil starvation and damage!! More commonly oil gets forced up through the PCV and gets sucked into the engine....not good in any sort of volume.

So....
Increased Pressure: Excess oil can cause excessive pressure in the engine, leading to potential leaks or seal damage.

Foaming: Overfilled oil can churn and foam, reducing its lubricating properties and increasing the risk of engine damage.

Reduced Lubrication: Foamed or aerated oil fails to lubricate engine parts effectively, leading to increased friction and wear.


So overall......dont do it!!