What went into making the new BMW 3 Series

Mark Smyth takes a closer look at the engineering behind the new 3 Series

11 October 2018 - 17:51 By Mark Smyth
The new BMW 3 Series
The new BMW 3 Series
Image: Supplied

Watching BMW’s press conference at the Paris motor show, it was possible to think that the reveal of the seventh generation 3 Series was not a big deal in a changing global market, one where BMW has changed production of the 3 Series after decades in SA to the new X3.

However, when the G20, the next generation 3 Series arrives in SA in March 2019, it will be as much a cornerstone of the brand as ever.

"Ten years ago, the SUV market was more or less dead," says Thomas Bauemer, head of project BMW 3 Series. "In 2008 we were thinking how long X5 will be around.

"Every fifth BMW is a 3 Series sedan. The SUV market is growing but up to now we have sold 50-million 3 Series over the past 40 years and it is still a very important market for us."

"It’s a huge segment," says Stephan Horn, head of product management BMW 3 and 4 Series. "Even though in some countries the sedan doesn’t play the role it played 20 years ago, the Touring (station wagon) is still part of the 3 Series family."

Many might criticise the new 3 Series for having a few elements that are a little too Lexus-like in terms of design, but it is more about what is beneath the skin — more tech, more comfort and more driving dynamics. Driving dynamics have always been a key characteristic of the 3 Series and the company is promising that the latest version will be even better.

"The core of BMW driving dynamics is still the 3 Series," says Robert Rothmiller, the man in charge of functional design and integration driving dynamics. He says that early in the project they determined it needed to be the ultimate sports sedan and it was never a question of how it should drive but how they can achieve that target.

Rothmiller says that to make the 3 Series better they needed to focus on handling, steering feel, acoustics, agility and precision. Internally they came up with the slogan "effortless fast" and he says that as an absolute basis for this you need "weight distribution front to rear balanced at 50:50, extra strength and, although the car is longer, wider and slightly higher than predecessor, it is up to 55kg lighter, again excellent for driving dynamics". The centre of gravity is lower by 10mm combined with a wider track, all of which make up one major pillar of the improvements to the car.

Take a closer look at the seventh generation of the all-new BMW 3 Series. We'll explore the exterior and interior design, explain features, such as the BMW ...

The second area has been optimisation of the combined stiffness of the body and chassis. Previously vehicle rigidity was measured at the jack mount points but this was not what you are driving on the road.

"Nowadays we are able to optimise the combined stiffness of body and chassis from the road surface through the tyres, through the axle kinematics, up to the body and up to the driver. The goal is to make the steering feel more precise because it’s the second generation of electric power steering. There were criticisms of the first generation, so we increased, for example, the mechanical feedback for the driver in the steering wheel."

Then Rothmiller says there also some new innovations in the latest generation car, including the introduction of a new damper technology. He says it’s "a kind of a damper inside of a damper", to provide additional shock absorbing forces at the front to reduce the rebound effect over bumps while at the rear the engineering provides the opposite with more compression through an additional piston inside the dampers. The changes improve sportiness and also overall ride comfort.

Models from the 330i upwards also get a new electronically controlled limited slip differential in the rear axle to improve traction and agility.

All this talk of driving dynamics is fascinating at a time when there is so much talk of autonomous driving and driver assistance systems.

"We balance the positioning of the car," says Horn, "On the one hand, our heritage — we must be the ultimate sports sedan and to ensure our competitors do not get close to us, we make the next step, very important. But on the other hand the industry is changing fast, there’s a lot of new technology coming in and we have to make sure the 3 Series is future proof."

But do not expect the new 3 to be able to drive you to the office when it arrives in SA in March 2019. Horn points out that it will be more Level 2.5 autonomous driving than Level 3, with driver assistance for highways such as lane keeping.

More Technology:

The new 3 Series has grown marginally in all areas, except possibly the interior which is similar to the outgoing version. But there will be more tech to make the G20 fit in more with our modern lives. This will include a personal assistant, similar to that offered by Mercedes and which you are used to with Siri, Alexa or Google.

Thomas Brenner of BMW’s digital department gave us a quick demo of the new assistant which is woken up by saying "Hey BMW". The system is more intuitive than we are used to. As an example, he told the car he was tired and so it lowered the temperature in the cabin and increased the music volume. Asking it for suggestions of places to go is also more interesting and the car can recognise who is asking — the driver or the front seat passenger.