Ever since the news broke that the next generation BMW M5 will be powered for the first time by a turbocharged engine, many BMW fans, and not only, have posed THE question: why a turbo engine and not the almighty NA powerplant that made us all happy?
After a discussion with Albert Biermann, head of development at M Division, Autocar UK reports that the decision was influenced by BMW's aggressive plans to cut fuel consumption as part of the EfficientDynamics programme.
"We've been forced to switch to an engine offering greater low-end torque than the naturally aspirated engine to ensure it can cope with the longer axle ratio," Biermann said. "It's the only real way we can balance achieving the environmental improvements we want while retaining similar levels of performance to today's car."
Could this be a concern? Sure, but if all the past rumors come true, BMW's use of new technology and even a KERS system will put the new M5 ahead of the current model, both in performance and fuel efficiency. Biermann estimates a 20% cut in CO2 emissions.
Since not all the details can be revealed way ahead of its launch time, the mystery around the engine used remains large. Based on our sources' reports and what other magazines reported, a V8 twin-turbo engine is the powerplant of choice in the new F10 M5. Output? Unknown, but we expect higher than the 555 ponies outputted by the X5 M and X6 M.
Biermann gets into more details regarding the turbocharged vs. naturally aspirated powerplant. While the 500 horsepower from the current V10 comes at 7,750 rpm, the V8's highest output should come before 6,000 rpm. But then we have the impressive torque coming from a turbocharged engine. Biermann indicates a 30% increase in torque, so that gives the new M5 around 500 lb-ft of torque at very low rpm.
The added power and V8 turbocharged engine requires additional cooling capacity and current test mules, seen in previous spy photos, are focusing on cooling solutions. The process is still at an early stage.
In the past, we reported that two gearboxes were being considered, an updated 8-speed dual-clutch gearbox (DCT) or a more advanced 8-speed SMG. Although we cannot confirm this at the moment, Autocar reports that the M5 will also get a new gearbox, a beefed-up version of the current M3's 7-speed DCT. The gearbox was featured last week on the M5 "CSL" at the 25th anniversary event at Nurburgring.
Even though a hybrid model is being considered in the 5 Series line-up, the M5 will not be featuring any sort of hybrid system due to the extra weight would add to the car. Another significant change in the next M5, is the control-arm front suspensions that will replace the MacPherson Struts and at the rear. This will be a multi-link layout.
With a car growing in size, a new large engine, M5's weight concerns are being addressed by using plenty of carbon fiber design elements. The newly unveiled wind tunnel in Munich will play an important role in the aerodynamics of the new M5. Autocar states that the car will get Active Aerodynamics, which blanks off parts of the grille and cooling intakes during warm-up and under light throttle load.
The F10 M5 will continue to feature different levels of ride comfort, leaving the choice to the driver.
Once again confirming some our previous reports on the new technology available in the next BMW M5, Biermann mentions a new, fully electric power steering that offers similar levels of response and feedback to today's hydraulic set-up.
The F10 BMW M5 will launch a year after the regular 5 Series models and the 2011 Frankfurt Motor Show would be the perfect venue.