dRockSL55

Does anyone know the reasoning behind the swap to single piston sliding rear calipers on the new r231 AMGs (And most other AMG models for that matter)?
I was studying a new SL65 at the dealer showroom and the sales team had no clue, and didn't even realize it was different than older models.
For years the AMG models had very attractive multi piston rear calipers. The new setup looks like AMG painted the front calipers of an 80s ford red and slapped them on the rear. The rest of the car is of course gorgeous, but I couldn't help but notice and felt it looked way out of a place on these top of the line performance Benzes. Was wondering if there was an actual performance benefit.

mellowyellow

I would guess the pistons are bigger, so you can have a 2 or 4 pot rear caliper with smaller pistons, or a single sliding one with a bigger piston. I doubt there is much performance difference. Before the R231 SL came out, I saw the CL63 and CL65 which also had sliding calipers all the way around, which I thought was really odd for an AMG.

The other interesting thing is that I was really interested in a 2013 SL63 with Carbon Ceramics, but it also had the rear sliding caliper even with that $12,625 brake option.

RacingBrake

Most likely is due to cost saving. It seems MB eliminates the rear drum emergency brakes and replaced it w/electro-mechanical parking brakes which only floating type caliper (also cheaper than fixed type calipers) can accommodate.

BMW made the same change about 2/3 years ago but now revert back to conventional rear drum brakes, so MB may well be doing the same later, after the new change.