Why does the 2008 BMW M3 use a sliding caliper for the brakes ?

Why does the 2008 BMW M3 use a sliding caliper for the brakes instead of a fixed caliper like most costly vehicles. IE Brembos. Is it for cost or utlilty?|||I will make you answer your question yourself by describing to you how a "sliding" and a "fixed" caliper works.


Remember that the brake rotor which is connected to the wheel is acted upon by two brake pads, one on each side. In a BMW just like most cars, there is only one piston that pushes one brake pad. So the whole caliper moves/floats/self-adjusts so that both brake pads can act on the rotor and stop the car.


In cars with fixed calipers there are pistons on both sides of the calipers.Some even have 2 pistons on each side. So the calipers do not need to self-adjust.


Obviously, the ones with more pistons costs more and are very slightly better in braking power. But being more complex and with more components they are also more prone to break down and costlier to maintain.


So did BMW try to save some money? Answer it yourself.|||Only BMW can answer that for sure, but I'm sure the calipers are cheaper, and from BMW's perspective, just as effective on a road car.





Car and Driver's recent comparison of the M3 against the Porsche 911 Turbo (and Nissan GTR) came up with 70-0 braking for the M3 of 158ft and for the 911 Turbo (which uses fixed calipers, and nominally has a better weight distribution for braking) of 154ft.





Fixed calipers are undoubtedly the choice for racing, make it easier to change brake pads, and make nice eye-candy, but the street car advantages are certainly arguable and limited.