World Premiere of the New BMW M5's Drive System

Press Release

The new V10 engine in the BMW M5

A masterpiece in engine construction

(Long version) The heart of every BMW is its powerful engine. It is more than obvious that this particularly applies to the models made by BMW M GmbH. This description alone, however, would not do justice to the new engine in the M5: modestly put, this ten-cylinder power unit is a milestone in modern engine construction. It is one of the most fascinating engines the world over ever to be used in a series-production vehicle. Some automobile aficionados also attach great importance to the sound of the engine. This is also the case with the V10: this technological masterpiece is to the sports vehicle aficionado what a symphony is to the ears of music lovers. Similarities to the sound of the BMW WilliamsF1 racing engine won't go unnoticed. The M5's V10 engine not only has got the same number of cylinders as its Formula 1 counterpart. Both engines also have the high-revving concept in common, a principle which generates enormous forward thrust from high engine speeds and is a characteristic of all high-performance, naturally aspirated BMW M GmbH engines. All this, in conjunction with the ten cylinders, results in an orchestra-like staccato, something that is normally only heard on the race track.

First high-revving V10 engine to be featured by a regular-production saloon

The new M5's high-revving V10, which has so far been reserved for racing cars and exotic low-volume cars, is the first engine of its kind to be used in a series-production saloon. In order to do justice to the exclusivity of the M family, this high-performance power unit offers a performance which is truly impressive: it has ten cylinders, displaces five litres, produces a maximum output of 507 bhp and a maximum torque of 520 Newton metres. Engine speed peaks at 8,250 rpm - a road-going athlete par excellence. But there is more to the engine than just impressive performance data. At the slightest movement of the gas pedal, the high-revving normally aspirated engine reveals itself to be a typical sports engine. At the same time, it is perfectly suited for use in daily traffic. The M5 is a saloon for everyday use with the heart of an athlete ¡¡ìC in other words, a roadworthy sports saloon. The M5 fully lives up to these two demands, opening up a new dimension of effortlessness. 20 years after the presentation of the first M5 marked the introduction of the segment of powerful sports saloons, this new engine once again points the way forward in this particular class.

Inspired by the Formula 1 engine

The engine was redesigned from scratch by the BMW M GmbH engineers. When constructing the power unit, the engineers drew inspiration from the BMW WilliamsF1 engine, which is generally regarded as the most powerful engine on the starting grid of the top echelon of motorsports. On the other hand, they transferred all M specific features from series-production automobiles, such as bi-VANOS, individual throttle butterflies and the most powerful engine electronics system currently available, an in-house development, as well as a traverse force regulated oil supply system. In order to create a worthy successor of the previous M5, which features a 400 bhp V8 engine, it was essential to do one thing: to increase performance even further. In engine construction there are three possibilities for boosting performance: increase the cubic capacity and raise maximum torque in the process, boost performance by using a turbocharger or a compressor or use a high-revving concept to increase torque.

Power is more than increased horsepower

There is more to it than pure output. Acceleration behaviour and driving dynamics are further important aspects, which are greatly dependent on the actual forward thrust and the vehicle weight. The forward thrust at the driven wheels is a result of both torque and transmission ratio. The high-revving concept contributes greatly to an optimum transmission ratio, which, in turn, helps to unleash impressive drive forces. When it comes to the laws of physics, the wheat is separated from the chaff, even if the engines under comparison are identical in output. If an engine's cubic capacity is increased, one has to put up with - for the benefit of high performance and torque - the problem of additional weight, more space required and higher fuel consumption. Supercharged engines also have drawbacks. Only rarely do they excel due to fuel economy and their spontaneity, i.e. the engine's ultra-fast response to the driver's inputs, fails to meet the high demands made of an M overall concept.

High-revving concept is the perfect solution

The third option, a compact, high-revving naturally aspirated engine, is the perfect answer. If only for the sake of tradition, for the BMW M engineers the following solution was the ideal choice: boosting performance by increasing torque. In this context it must be said that, from a technological viewpoint, the high-revving concept is far more sophisticated, so that it is much more difficult to put this concept into practice. After all, it is no coincidence that BMW's introduction of the new M5 has made them the first manufacturer worldwide to position a high-rpm V10 engine in the segment of powerful final production sports saloons. Offering a maximum speed of 8,250 rpm, the ten-cylinder engine has ventured into terrain which has up to now been reserved for thoroughbred racing cars. By way of comparison: the previous M5's engine speed is electronically limited to 7,000 rpm. The new ten-cylinder powerplant has broken the 8,000 rpm barrier.

Formula 1 technology takes to the roads

With this new engine beneath the bonnet, the M5 redefines what is technologically feasible in the manufacture of series-production engines. The higher the torque, the closer the engine gets to its limits. The following comparison gives you an idea of the immense stress acting on the material: at 8,000 crankshaft revolutions per minute, each of the ten pistons covers a distance of approximately 20 metres per second. Coming back to the ten-cylinder engine in the BMW WilliamsF1: at 18,000 rpm, the pistons move as much as 25 metres per second. The difference is, however, that a Formula 1 racing engine only has to travel 800 kilometres in one racing weekend, whilst the M engine must last the lifetime of the vehicle, regardless of the climate, traffic situation and style of motoring. It is evident that the M5 engine has various basic technological principles, production methods and materials in common with the Formula 1 engine and that it is based on technological transfer.

A 25 percent plus in performance - a new dimension of driving dynamics

The completely redesigned V10 engine, a high-revving ten-cylinder powerplant, is superior to its predecessor, which features 8 cylinders and the same cubic capacity, in all disciplines. Proof of this is provided by its performance which is up by more than 25 per cent. The new V10 engine produces a maximum output of 507 bhp (373 kW) at 7,750 rpm (maximum output of the V8 is 400 bhp - 294 kW - at 6,600 rpm). Weighing in at just 240 kilograms, the new ten-cylinder engine is almost identical in weight with its eight-cylinder forebear. Given its awe-inspiring performance, the new ten-cylinder engine is a real lightweight. However, the engine is a heavyweight when it comes to its output per litre: the ten-cylinder M5 exceeds the magical mark of 100 bhp per litre of cubic capacity, its specific output being on par with that of racing cars.

Engine speed has a major influence on performance and torque

As far as maximum torque (520 Newton metres) is concerned, the ten-cylinder matches the eight-cylinder power unit. Nevertheless, the new M5 beats its predecessor in all disciplines relating to driving dynamics. This phenomenon is also connected to the engine speed. A case in point: If a cyclist changes down when going uphill, he must pedal faster but he will master almost every gradient no matter how steep. If he does not change gears or if he even changes up, he needs a lot more energy or he has to get off the bike. If there are two cyclists with the same amount of stamina, it is always the cyclist who pedals faster that wins the race. The logical consequence is that the new M5 with its high-revving engine also effortlessly outdoes all direct competitors who exclusively rely on the "torque concept" of an eight-cylinder engine with an increased cubic capacity. In addition, this engine's superiority can be put down to the fact that the concept-related extremely high torque of competing engines has to be transferred via a massively reinforced and heavy drive train - added weight and mass that must also be accelerated. Thanks to the V10's high-revving concept, a considerably lighter drive train can be used and closer gear ratios can be achieved. By the way, the new M5 also outdoes its competition when it comes to torque: peak torque of 520 Newton metres is reached at 6,100 rpm, a torque of 450 Newton metres is already obtained at 3,500 rpm. And 80 per cent of maximum torque is available at up to 5,500 rpm, which is a wide speed range for an engine of this calibre. By way of comparison: the sporty and most powerful engine in the BMW 545i offers a maximum torque of 450 Newton metres.

Even superior to twelve-cylinder engine

The ten-cylinder engine is truly superior to its eight-cylinder competitors and, at the same time, does away with the design drawbacks of a twelve-cylinder powerplant, which, due to the number of components and the filling quantities, is larger in its dimensions and heavier than the compact ten-cylinder engine. Increased fuel economy due to lower frictional losses incurred by a reduced number of components is a further advantage of the ten-cylinder engine. The new V10 therefore represents the perfect solution for a car such as the M5. In addition, the ten cylinders with a displacement of 500 cc each, fully live up to the ideals of the most discerning engineers.

Compact design for increased robustness and comfort

BMW, one of the leaders in engine construction, has made a name for itself primarily as a manufacturer of inline engines. When constructing the new ten-cylinder engine, the engineers arranged the two five-cylinder banks at an angle of 90 degree (V-configuration) with a 17 mm offset to create a compact aggregate. The 90 degree angle has been chosen due to its low-vibration and comfort-oriented mass balancing properties. In its geometry the engine solves the conflict between minimum vibrations and maximum component robustness. The cylinder crankcases are cast utilizing the low-pressure gravity die casting method and are made of hypereutectic aluminium-silicon alloy. This special alloy contains at least 17 per cent silicon. The cylinder liners are created by precipitation of the hard silicon crystals. Additional liners are not necessary ¡¡ìC the iron-coated pistons run up and down in the uncoated bores. Stroke is 75.2 mm, bore is 92 mm, overall cubic capacity amounts to 4,999 cc. By the way, the blocks for the M5 engines are cast at the same place as the Formula 1 engines: at the BMW light alloy foundry in Landshut.

Bedplate derived from racing technology

High engine speeds, high combustion pressures and high temperatures put an enormous strain on the crankcase. Therefore the engineers have chosen the so-called bedplate design, a compact and extremely stiff configuration which is derived from car racing. The new engine in the BMW M5 is the first series-production V engine to feature such a bedplate design. The aluminium bedplate with integral grey-cast iron inserts ensures high-precision crankshaft alignment, keeping the main bearing clearance over the entire operating temperature range at a minimum. The grey-cast iron inserts help to reduce the thermal expansion of the aluminium casing. To ensure positive coupling with the adjoining aluminium frame, the inserts have been provided with openings. At the same time, this architecture contributes to fulfilling the demands made of the M5's engine acoustics. The extremely stiff and finely balanced crankshaft made of forged, high-tensile steel is supported by six bearings and weighs a mere 21.8 kilograms. It balances inertia forces and is designed for maximum torsional stiffness. The main bearing diameter measures 60 mm at a bearing width of 28.2 mm. Two con rods connect to each of the five crank pins, which are offset at an angle of 72 degrees. A reduced cylinder spacing of only 98 mm enables the use of a short crankshaft, thus resulting in high flexural strength and torsional stiffness, as well as a very low weight.

Every gram counts in lightweight construction

The weight-optimized pistons are made of high temperature resistant aluminium alloy and are provided with an iron coating. They weigh a mere 481.7 grams, including piston pins and rings. The compression height is 27.4 mm at a compression ratio of 12.0:1. The pistons are cooled using oil spray jets which are directly connected to the main oil duct. The 140.7 mm long, low-weight, fracture-split trapezoidal connecting rods are also made of high-strength steel and effectively reduce the oscillating masses. Each of the ten connecting rods forged from 70MnVS4 has a weight of only 623 grams, including the bearing shells. The single-piece aluminium cylinder heads of the V10 engine are also produced at the BMW light alloy foundry in Landshut. The cylinder heads feature integrated air ducts for air injection which is important for rapid catalytic converter warm-up. The cylinder heads incorporate four valves per cylinder, a BMW specific engine architecture. The valves are actuated by spherical tappets featuring hydraulic valve play compensation. The tappet diameter has been reduced to 28 millimetres and its weight is down to 31 grams. Through optimisation of all parts and components of the valve train, the moving mass has been reduced by 17.5 per cent in comparison with the predecessor model. The diameter of the intake valve is 35 millimetres, the exhaust valve measures 30.5 millimetres in diameter. The shaft diameter is 5 millimetres.

Innovations with attention to the smallest detail reduce maintenance costs

The intake valves are exclusively manufactured for the M5 engine. With a reduced shaft measuring only 5 mm in diameter, there is hardly any impedance of the flow in the intake tract. Hydraulic valve play compensation units automatically provide for the optimum valve adjustment at all times, which is beneficial to the customer as it lowers maintenance costs. The higher the engine output, the higher the need for cooling the engine, particularly in the vicinity of the combustion chamber. Compared to conventional systems, the crossflow cooling concept of the M5 engine considerably minimises pressure losses in the cooling system. It ensures an even temperature distribution in the cylinder head and the reduction of peak temperatures in critical areas of the cylinder head. Every single cylinder is evenly supplied with the optimum amount of coolant which flows from the crankcase at the outlet side through the cylinder head and via the manifold strip at the intake side to the thermostat or cooler.