The 2.5 turbo does not have an ECU that controls fuel delivery - the ECU system in this car is responsible for boost, EGR and idle speed control.

The 2.5 turbo boost control system makes the car seem faster than it really is - turbo spool-up is very fast. I've not driven a non turbo OM606 but I agree with the previous poster, I suspect they would be about the same.

Now if you are really interested in a little more power look for a W210 OM606 turbodiesel...