BMW’s M Division, yes, the same people shoe are responsible for the amazing M3 and M5 models, have announced recently that they are going to focus on removing weight from their cars, rather than adding more power. This move comes as a result of the need to increase power-to-weight ratios, but without adding more power, something that is becoming increasingly difficult as a result of tightening emissions regulations.
“We want to be in a different league for power-to-weight,” says Carsten Pries, the head of M product management, “but we prefer to have a car that weighs 1,000kg rather than one with 1,000 horsepower.”
This trend can already be seen in the latest models of the M3 saloon, and the M4 coupe. Whilst both of these cars are more powerful than the models that they replace; the increase is only 3 per cent, from 416bhp to 427. Weight, on the other hand, has dropped by up to 80kg, or 6 per cent. Already, the benefits of this move can be seen, with fuel consumption and CO2 savings of up to 28 per cent. Or, in English, potentially another 100 miles on a full tank of fuel.
Adding to the weight-saving crusade is the fact that the front ends of both models are now almost exclusively built from light-weight aluminium, with carbon fibre and magnesium sections in the drivetrain and structure. Further contributing to the regime is the of improved economy and reduced emissions is a new twin-turbo six cylinder engine to replace the older V8 from previous models, and the availability of a double-clutch gearbox.
This desire to save weight is the primary reason why BMW M have decided to ditch the xDrive all-wheel-drive system in favour of rear-wheel drive. “What is the point of taking out 80kg if you are going to put 75kg back through xDrive?” says Pries.
“It does not mean that we will not have xDrive in an M model in future. On Thursday I am going to a customer event in Istanbul, and sometimes these give us early indicators of changing preferences. But many M3 customers like to take part in track days, and they prefer the feeling of rear drive.”
The new M3 and M4 go on sale on June 21 priced from £56,175 and £56,635 respectively. In September a new M4 Convertible, costing from £60,745 and exhibiting a similar weight loss to the saloon and coupe, will join the range. BMW expects to sell around 5,000 M3 and M4 cars over their lifetime, with a peak of 1,200 next year.
Simon Davis, June 2014.
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