Australia

I have a 2003 bi turbo CL600 V12 . i am looking at Renntech or Speedriven air cleaner and intercooler upgrade with ECU+TCU tune. I wonder which one is best of the 650-680 HP ranges both list.

Any advice would be much appreciated on ease of instalation, running experience and technical qualities.
Roger down under

RoadHazard

I prefer Speedriven, though I have considerable bias. I believe that because they're a smaller tuner, they have more to prove, and they've done so with building the fastest V12TT's on the market. I find their products to be far more dedicated to values I saw in the pre-merger AMG, a no-holds-barred approach to making tons of power and tons of speed. Renntech offers rear-view cameras and pretty carbon-fiber airboxes. Speedriven offers "off-road use only" downpipes and giant turbos. I think that's more than enough of a reason to go with the latter. Good luck on wherever your modding path takes you!