BMW M5
For the first time, BMW’s latest performance sedan gets a smaller engine than its predecessor – fuel consumption is down, output is up, and it’s quicker than ever
- Published in Features.
M5: An ordinary-looking executive sedan with sportscar performance
When BMW’s motorsport division decided to put the 3.5-litre straight six from its mid-engined M1 coupe into the 5 Series, it created a niche: an ordinary-looking executive sedan with sportscar performance. The first-generation M5 appeared in 1985, when 210kW was enough to get it to 100km/h in 6.5 seconds and 245km/h flat-out. That’s quick even today, and every model since has received a bigger engine with more power.
Until now. A twin-turbo V8 replaces a V10. The V10’s CO2 emissions pumped out of the vehicle’s four tailpipes were not helping BMW’s fleet average or image as the premium carmaker tried hard to reduce fuel consumption.
Albert Biermann, BMW M’s head of development, says: “We cannot continue with cars that have carbon dioxide emissions above 300g/km. So we have to find the technical concepts to reduce the side effects, so to speak, of driving an M car.
“Driving pleasure is a little bit like a drug – with the new M5 the concentration is higher, but the side effects are much lower. So that’s our job: to keep increasing the pureness of driving pleasure and at the same time make it more socially acceptable is M’s challenge for the future.”
Whatever vehicles M will be making in 2020, the basic development process will be the same as it is now: its engineers are always looking at what’s coming up in BMW, from the very early stages, and working out how to improve things.
In parallel with the series programme, Biermann’s team defines the concept for the M version. Powertrain and chassis are bespoke. So too, as a rule, is everything else that connects the driver to the road surface. This can mean changes are made to the base model to support this activity but there’s always a business case to answer. “Parts such as the steering column we don’t touch, as long as we think they’re robust,” Biermann says. “If it wasn’t stiff enough, we would change it. But the body shell of the 5 series is excellent. If it wasn’t then we would not have implemented our rear-axle concept.
“We had the idea on the M3 GTS and the M3 GT4 racecars of directly bolting the rear axle carrier to the body shell – we brought this concept into the M5. It’s lighter and improves precision, especially driving on racetracks. There is an NVH downside so we had to meet our targets for that too.”
Setting technical targets is complex but the development objectives were easy to define: better performance and handling on the road and track, better driving comfort in daily use, and much lower fuel consumption. Benchmarking was easier still because the process involved only one vehicle: the old M5. “We don’t look much at what everybody else is doing,” he says.
The previous M5 appeared in 2004 with a naturally aspirated 5-litre V10. The engine made a lot of noise, and had a lot of power – 373kW – but had to be revved to 7,750rpm to deliver it. This was a lot of fun, of course, but also burned a lot of fuel.
By the time work had started on the next-generation model, Europe’s fleet-average CO2 targets had been set, which meant that high-consumption, high-performance vehicles were becoming less attractive to consumers and to carmakers.
