First details: BMW M5 V10 packs 378kW

BMW has revealed first details of the bahnstorming, Formula One-inspired V10 that will power the Munich maker’s next M5 sports sedan when it goes on sale here mid 2005.

Underlining the importance of the latest M model’s powerplant is the radical departure from the V8 motivation of previous M5s. BMW hopes the new 5.0-litre V10 engine will draw valuable parallels with its high-revving, high-output BMW WilliamsF1 counterparts.

Despite early reports that insisted the new M5 engine’s output would better the 411kW performance peak of the benchmark-setting Bentley Continental GT’s 6.0-litre twin-turbo W12, the E60 M5 will produce a still-handy 378kW.

BMW makes much of the naturally-aspirated V10’s ability to deliver healthy performance across its entire rev range, but key figures including a 378kW (507bhp) power output, 520Nm of torque and an 8250rpm redline will make the next M5 the most powerful production model in the BMW line-up.

Easily surpassing the lofty 100hp-per-litre specific output that’s been the domain of racing engines and high-performance cars including BMW’s own M3 for some time, the new engine realises a significant 25 per cent power increase over the outgoing 298kW 5.0-litre M5.

A 90-degree V10 with two five-cylinder banks, the new engine is claimed to deliver the best compromise between performance and vibration by incorporating a bedplate alloy crankcase design with grey-cast iron inserts to enhance acoustics, reduce vibration and ensure a high oil supply rate.

What’s described as an extremely stiff crankshaft is supported by six bearings, while the one-piece cylinder-heads accommodate four-valves per-cylinder – each of them achieving new levels of weight-saving due to lightweight, 5mm-shaft valves, spherical valve tappets with hydraulic valve play compensation and single valve springs.

Of course BMW’s bi-VANOS infinitely variable inlet and exhaust valve timing system is fitted, while 10 flow-optimised intake trumpets inhale air their charge from two intake plenums. Each cylinder has its own throttle, which are actuated simultaneously and electronically controlled.

E60 M5’s full dual exhaust is made of seamless stainless steel and features the M-trademark four tailpipes and is a Euro4 and US LEV2 emissions-compliant. MS S65 engine management is used.

M5 will also introduce what’s being claimed as the world’s first seven-speed sequential gearbox with drivelogic function. A further development of the six-speed Sequential M Gearbox, the seven-speed SMG continues with a (more refined) automatic mode with 11 shift options, a conventional gearshifter and steering wheel-mounted shift paddles, but the new transmission is said to offer a 20 per cent reduction in shift times.

Six of the transmission’s shift programs are available in SMG mode (S mode), ranging from “balanced dynamic to very sporty”, while a Launch Control function continues from the previous SMGII (which was never available with the current M5).

In Drive mode the SMG uses all seven ratios as required according to road speed and accelerator position. An anti-roll feature also prevents the car from rolling backwards during hill starts.