I'm going to use both.

The mechanical fan and a pair of Proform 67010 fans in front of the condenser. I do plan on measuring the pair of electric fans that are in front of the condenser currently on the CLK430..... they may work for me.

It's a "better safe than sorry" kind of deal. I could probably get away with the electric fans...… but there is obviously a reason why MB decided to use a mechanical fan for the V8's. Technically, they only rob HP when the engine is hot enough for the clutch to engage..... otherwise they just kind of pinwheel.

Jared