Herbert Diess, BMW's global R&D boss, is overseeing the launch of the i3 electric vehicle as well as the introduction of a new front-wheel-drive architecture and modular engine family.
Q: By 2016, BMW Group plans global annual sales of two million vehicles, including the Mini brand. How many vehicles will use your new fwd architecture?
Diess: Today rear-wheel drive represents slightly more than a million. As to fwd, we currently only have the Mini range, with sales of about 300,000 units. In the next few years, the share of smaller vehicles in BMW Group sales worldwide will increase: 40% within five years is not unrealistic [from about 30% now].We will be offering those vehicles with front-, four-wheel and hybrid-drive systems. Rear-wheel drive, however, will remain the BMW Group's most favoured drive system.
Q: BMW has a third vehicle architecture for the low-emission i vehicles called LifeDrive. This is an aluminium chassis with a carbon-reinforced plastic body. Could it be used for conventional powertrain models?
Diess: LifeDrive is really an architecture for new drivetrains, mostly electric and plug-in hybrid-based. It doesn't make sense to use that kind of architecture for conventional cars. We think in electric and plug-in cars it makes sense because we can reduce the size of the battery, which is the most expensive component in the car. If I can reduce the weight of the car proportionately, I can reduce the size of the battery and the battery is even more expensive than the carbon fibre.
Q: In conventional cars you already use carbon fibre, for example, on the roofs of the M models. Will this increase?
Diess: Yes. We will identify more parts where it makes sense to use carbon fibre. Future body structures will mix aluminium, steel and carbon. But it will be awhile before we use carbon at the same large scale at which we currently use steel and aluminium.
Q: The new family of modular three-, four- and six-cylinder engines will become the largest within the BMW Group, powering about 1.5 million of your 2 million sales planned in 2020. When will the first engine debut?
Diess: Next year. A three-cylinder unit will be the first application.
Q: Which model will be first?
Diess: The BMW i8.
Q: Will future V-8 and V-12 engines be spun off this new engine family?
Diess: Mechanically there will be not many common parts, but the engines will be closely related in terms of technology.
Q: Will V-8s and V-12s disappear?
Diess: We still see a market for gasoline V-8s and V-12s, so we do not have any plans to abandon them.
Q: Could we see a BMW V-8 diesel again?
Diess: No, our six-cylinder diesel engine with three turbos is fantastic. It's lighter, but has the same torque and is very responsive.
Q: BMW will offer a small engine to extend the i3 EV's range. Isn't this a contradiction for a "born electric" model?
Diess: The optional range extender will almost double the range of the BMW i3. We do not think that a substantial share of customers will really need the range extender. It is more of an issue for those who have not yet had a chance to use an electric car. After a few days, they usually discover that a base range of [100 miles] is sufficient to limit recharging to about two times a week. In most cases where people first think they need a range extender it actually never is used.
Q: BMW envisions i3 buyers using the battery power for urban daily commuting and the range extender just for occasional longer trips. What about those using the range extender on a daily basis?
Diess: The range extender is not intended for daily use. It's for situations when the driver needs to extend the range of the vehicle to reach the next charging station. Therefore, the i3 probably won't be the choice for customers with a need for an extended range. A plug-in hybrid would be a more suitable solution.
Q: What is the ideal balance between battery cost and pure electric range in a plug-in hybrid model?
Diess: Our experience with real customers driving our electric vehicles shows that in cities daily average mileage is below [19 miles]. The Chinese currently say you have to deliver [31 miles in electric-only range], which from our perspective surpasses the ideal balance.
I would say the target range should be far enough so that recharging isn't needed more than twice a week when using the car in urban surroundings.
Q: Europe, the US and China are setting more stringent emissions standards. What will be the toughest to reach for BMW?
Diess: In terms of carbon dioxide, we expect Europe to set the toughest fleet targets. From the emissions side, the Zero Emission Vehicle mandate in California is the most ambitious because it creates a future market for electric vehicles and probably even fuel-cell vehicles.