Mercedes c240 4matic: permanent AWD?

Question

I plan to buy a car (a Mercedes c240 4matic from 2003) with AWD. I heard, all-wheel drive is really good in winter, and maybe on the mountains. But in sommer it's only a waste of gas. The engine has 170HP. Is it possible do deactivate the rear-wheel drive of 4matic? Could this lead to the damage of the engine or any other parts of the car?
Does somebody has experience with 4matic? Somwhere i read, that (at least in the models before 2000) the 4matic has a "supporting" function: the front tires are driven, if the rear ones begins to spin. But in the service center, they told me, that 4matic is a permanent AWD (maybe in the brand new models?). Here is an interesting post: Difference between FWD/RWD/4WD/Part-Time 4WD/AWD? I'm not sure, what exactly 4matic is.

Thanx in advance, Daniel

Answer 1

I think in the C240 it is a permanent 4Matic system. As you can buy the C class without 4Matic as well.

The clever systems of 4Matic wont effect fuel consumption so much so that its a deal breaker in my opinion. You could have this in the earlier (1995-1999) to turn them off but again this would have left a warning light on your dash. Which would indicate that even then it was not recommended by Mercedes, otherwise they would simply have added in a button to switch it off..

4X4 systems differ a lot from brands as well as models, so if you want accurate information on how good it is, then you should look specifically at the 4Matic posts.. Here is an excellent review of a newer version but can still be compared to your model:

Mercedes 4MATIC AWD System Review