BMW has revealed its latest executive express with the official unveiling of the M5 sedan - the first fully-fledged M sedan to ditch rear wheel drive in favour of a new, switchable all wheel drive system.
Under the bonnet the new M5 packs in a re-engineered version of the previous generation’s 4.4-litre twin turbo V8 with outputs of 441kW and 750Nm, a step-up of 18kW and 70Nm compared to the most powerful regular-production version of its predecessor.
Thanks to those more prodigious outputs and the extra traction afforded by the M xDrive all wheel drive system BMW claims the new M5 can bolt from 0-100 km/h in just 3.4 seconds, down from 4.2 seconds compared to the outgoing M5, making it the most powerful and quickest M5 yet.
That all wheel drive system could be the most controversial addition to the M5, which has traditionally been lauded for its rear wheel drive dynamics. The new M xDrive system is a development of BMW’s standard xDrive set-up with unique software capabilities that allow to to revert to rear wheel drive in its most extreme ‘track only’ setting.
“Thanks to M xDrive, the new BMW M5 continues to offer true rear-wheel drive like driving traits as well as significantly enhanced directional stability and controllability right up to the limits of performance, even when driving in adverse conditions such as in the wet or snow,” Frank van Meel, the head of BMW M said.
Like the regular 5 Series range (as well os the new 7 Series and X3) the performance hero adopts BMW’s latest CLAR product platform (which stands for CLuster ARchitecture) endowing the new model with a body that is both lighter and more rigid.
To help the M5 stand apart from its regular counterparts unique M components, including a deep front bumper with massive air intakes, a unique bonnet with additional feature lines, wider front guards featuring engine bay air extraction vents, wider sills, specifically-designed door mirrors, a beefed-up rear diffuser, and a subtle lip spoiler contribute not only to a more aggressive look, but also help with aerodynamic performance.
The new sixth-generation M5 is also the largest yet, length extends by 55mm to 4965mm, width grows by 12mm to 1903mm, and height rises by 16mm to 1473mm. Despite the larger dimensions and the addition of AWD hardware BMW has managed to cap the new model’s weight gain to a respectable 25kg over the car it replaces at 1855kg.
BMW has pulled weight were possible with features like an Aluminium bonnet, carbon fibre roof, 70Ah lithium ion battery, and a lightweight exhaust system.
In order to squeeze extra performance out of the 4.4-litre engine, the heavily revised V8 features new turbochargers, a revised intercooler, increased fuel injection pressure of 350 bar and a new high capacity oil pump for more reliable oil scavenging under extreme driving conditions.
M devotees will note that the new engine (which is identified by its S63 internal designation) matches the power output of the earlier M5 30th anniversary model produced in a limited run of 300 in 2014, albeit with an added 50Nm of torque.
Next to its chief rivals the new M5 keeps up, without providing an clear advantage in the case of the 450kW/750Nm Mercedes-AMG E 63 S 4Matic and its twin-turbocharged 4.0-litre V8 but manages to out-torque the the 445kW/700N Audi RS6 Plus, which is also powered by a twin-turbocharged 4.0-litre V8.
Another significant change to the new model sees the previous generation’s Getrag-build seven-speed dual clutch automatic transmission replaced with a new eight-speed torque converter automatic developed by ZF, though the new automatic is still available with a choice of three different driving modes as well as a full manual mode for sequential shifting.
The new M xDrive all wheel drive system is based on the hardware of the regular xDrive-equipped 5 Series with the addition of BMW’s Active M Differential and a software system that uses in-house developed code that ensures the front wheels are only engaged in situations where the rear tyres have run out of grip.
Purists will be able to engage a 2WD mode for the xDrive system that locks the car into rear wheel drive, but only becomes available with the stability control off, although those that would like to combine a degree of electronic support with their driving thrill will be able to incite “easily controlled drifts” in 4WD Sport with M Dynamic Mode engaged, accordign to BMW
The handling gurus at M have also set to work on the M5’s suspension which uses a heavily modified version of the standard 5-Series’ double wishbone front and five-link independent rear suspension. Relocated wheel carriers see the wheelbase extended by 7mm compared to a regular xDrive 5 Series and 26mm compared to the previous car at 2982mm.
Additional bracing and aluminium transverse struts at the rear increase the stiffness of the suspension linkages and the track has been widened by 26mm at the front to 1626mm, while the rear track is reduced by 2mm at 1595mm.
The tuning of the M5’s suspension has taken place predominantly at BMW’s Miramas test track in southern France and the Nurburgring circuit in Germany. Lightweight alloy wheels come in a standard 19-inch diameter with 275/40 front and 285/40 rear tyres or optional upsized 20-inch rims with 275/35 front and 285/35 rear tyres.
Alongside the regular M5 BMW will also offer a special First Edition model limited to just 400 vehicles finished in Frozen Dark Red matt paint with gloss black applied to the grille, front guard vents, tailpipes, and double-spoke alloy wheels.
Pricing details for the new M5 are yet to be revealed, though potentials buyers can expect a moderate increase on its predecessor’s $229,000 price tag in line with its added performance potential and increased level of standard equipment.
MORE: BMW News and Reviews