What is it?
It might seem odd to describe a near-£90,000 BMW M4 as the middle-of-the-range model, but that’s exactly what the M4 CS is.
The justification for that £89,130 price tag is the use of some of the GTS’s exotic weight-saving parts. Truth be told, though, all you’re really getting from the hardcore model are its carbonfibre bonnet and lightweight door skins (more of which in a moment).
It isn't as though the CS also borrows the GTS’s trick water injection system or its fancy manually adjustable suspension. Instead, it simply uses a revised version of the same adaptive damping system that you’ll find on the standard M4.
It does get an uplift in power compared to the M4 Competition Package, though. (That’s the model that carries a modest £3000 premium over the standard M4 and lifts power and torque to 444bhp and 406lb ft.)
The CS has 454bhp and 443lb ft, which has been achieved simply through new engine management software. The CS also gets Michelin Pilot Sport Cup 2 tyres - the same rubber used by the GTS.