With an eight-percent quicker steering ratio and the enormous V-12 and wide wheels limiting the amount of steering lock, the flat-bottom steering wheel makes only two turns lock to lock. The car's turning radius is enormous, a problem that's compounded by a low, delicate, and very expensive carbon-fiber splitter - and the oil cooler that's mounted directly behind it. The car's steering is accurate and offers good on-center feel, though nothing like the feedback in the CLK63 Black Series. Effort builds very nicely - light on-center, the steering becomes quite heavy at maximum cornering, reminding the driver of the car's near 4500-lb weight.
The SL generates enormous grip, helped no doubt by its wide-body stance. With track increased by more than four and a half inches up front and four inches in the rear, the Black Series is a very wide machine. When you're far enough away to see only its proportions, you'd think it was a Ferrari or Lamborghini coming up behind you. On the highway, the SL's interior is quiet, peppered with the drone from the V-12's exhaust. From the outside, the engine is loud, but it's not the heart-warming shriek of the V-8 AMGs - it sounds more like a jet helicopter than a muscle car.
We had the opportunity to drive the Black Series both on the street and on the track at Mazda Raceway Laguna Seca - the latter definitely being the preferable locale for tiptoeing up to the SL's very high limits. At track speeds the Black Series is astonishingly composed. The thrust of the V-12 is commendably controlled despite the inherent turbo lag. A short time after you apply throttle, the boost hits like a heavyweight boxer, and will knock the Black Series' rear end off line. Despite the weight AMG was able to remove from the car, the enormous V-12 up front means that under a steady throttle the Black Series is prone to understeer. The SL63 AMG is better balanced, thanks to its lighter V-8, and is far more throttle-adjustable, since the normally aspirated engine's power delivery is immediate and linear. The lesser SL's electronic brakes offer no feel, however; its narrower track make for less ultimate grip; and its engine provides less thrust. The much less expensive SL63 may be more communicative, more visceral, and more fun, but on a big racetrack like Laguna Seca, which rewards high-power cars, it's not as fast.