The S63 and CL63 have been updated to include AMG’s newest motor, the direct-injected 5.5 liter twin turbo. Along with the engine stop start system found in the S400 these new models provide more horsepower with increased fuel economy. It will be interesting to see if the addition of the stop start system will eliminate the wonderful rumble the current cars produce at start-up or if everyone around will now hear this every time an AMG fires up to leave a stop light. Another great benefit of going to a twin turbo setup is that it will be much easier to increase power output over the coming years or much sooner for with a quick visit to Kleemann or Renntech. The new motor’s increase to 571hp and 663 lb-ft of torque should keep you entertained for a while but it’s good to know that there is more power available when you’re ready.