M division aims its M5 super-saloon at unmatched heights. Does it hit the target?

PHOTOGRAPHY LUCLACEY

MODEL TESTED M5 CS

Price£140,780 • Power626bhp • Torque553lbft • 0-60mph3.0sec • 30-70mphin fourth3.8sec • Fueleconomy18.5mpg • CO 2 emissions256g/km • 70-0mph40.8m

We like

• Goes harder and sounds better than anyM5for generations

• Suspension and axle geometry changes yield transformative results

We don’t like

• The ultimate M5 definitely costs ultimate money

• The UK’s model allocation is already all sold

W hen appearing on the bootlid of a fast BMW, ‘CS’ originally stood for either Competition Sport or Club Sport – depending on exactly when it was applied, and to what. That might lead you to expect this week’s road test subject to be some stripped-out racing machine, but it isn’t.

The CS model suffix has, in fact, been used of late by BMW’s Motorsport in-house tuning division to identify all kinds of extra-special M cars, and now it’s being used on a ‘Club Sport’ model of a bigger and more powerful size altogether: the £140,780 BMW M5 CS super-saloon.

This car refines and enhances the mechanical recipe of the M5 Competition inanumberofwaysthat may seem quite subtle on the face of it. Their aim, however, is to produce a performance car of very special status: the most powerful road-going BMWMcartherehasever been, for one –but also the ultimate M5.

In that lofty pursuit, M division has resisted the lure of turning this car into some four-door track-day monolith and instead cherished and honoured the M5’s enduring usability as a road car.

It has become such a habit of BMW to use later-model-life special editions to fully uncork the dynamic potential of itsMcarsthatwe predicted the appearance of this car in our 2018 road test of the current, F90-generation M5. We wrote: “If BMW M history is any guide (think F10 M5 ‘30 Jahre’, F82 M4 CS and others), the very best version of this M5 may beyetto come. And when it does come, it ought to be something very special indeed.”

Time to find out exactly how right we were.

DESIGN AND ENGINEERING

★★★★☆

A good dose of exposed carbonfibre anda rather fetching new brightwork colour that BMW calls ‘gold bronze’ are the key material themes in the exterior design makeover of the M5CS.The car has satin bronzecoloured kidney grilles and wheels; carbonfibre-edged air vents in its new bonnet and front bumper; and an all-new front splitter, boot spoiler, rear diffuser, and door mirror covers in carbonfibre, too.

BMW’s engineering changes have been driven by several aims, one of which is weight-saving. The CS’s carbonfibre-reinforced plastic (CFRP) bonnet, standard-fit 20in forged wheels, standard carbonceramic brakes, interior tweaks anda host of detail revisions have supposedly saved 70kg from the kerb weight of a stock M5 Competition. Aswe will explain later, it wasn’t a saving that amounted to much on our proving ground scales. But then the M5CS isn’t some stripped-out circuit special like an M4 GTS but aluxury performance car that comes fully loaded with digital technology and equipment.

Range at a glance

TRANSMISSIONS

8-spdautomatic ■

Unlike the cut-down equivalents of rival brands, the BMW5 Series derivative line-up still reads like a restaurant menu. Even among lighter-touch performance models, there is both the M550i xDrive and the 545e to choose from. BMW doesn’t offer the non-Competitionspec M5 in theUKany more.