Meeting of minds Hybrid supercars debated
Prius blazed the trail – but now the hybridisation of supercars is gathering pace. Christian von Koenigsegg and McLaren’s Jens Ludmann compare notes
Mounting pressure to reduce emissions is driving the likes of McLaren, Ferrari and Aston Martin to electrify their core ranges – and not just their big-money, Speedtail-style flagships. Motorsport has proved the good sense of turbo engines and electric motors working in concert, but squaring the advantages of electrification with the weight penalty batteries inevitably bring will not be easy…
Jens Ludmann: ‘Emission requirements are undoubtedly driving the move to performance hybrids, but it’s also about the torque-feel of an electric motor, the instant response: this is very good when you are engineering a sports car. And with a hybrid you still have something of the power-to-weight ratio of a combustion engine. By 2024 all Sport Series [570S and friends] and Super Series [720S] McLarens will be hybrid.’
Christian Von Koenigsegg: ‘Before the Regera, I was quoted many times saying I did not like hybrids. But there is a big difference. It is the parallel hybrid [Prius, McLaren P1] I disliked: a full combustion engine and then, in parallel, electrification. This is complicated, expensive and heavy, since you are adding to the system but not removing anything. Series [BMW i3] is simpler, and you can remove the gearbox. The result is cheaper and lighter but you have increased losses, since you are converting mechanical movement to electricity and then back to mechanical movement. The engine is disconnected from the driving experience, so you have neither the serenity of an EV nor any sense of connection to the engine.’
JL: ‘When you go for electrification, it makes sense to have a powertrain developed as a unit. It doesn’t make sense to have an engine that hasn’t been developed to work with the punch of an electric motor. But at McLaren the cars we do are driver’s cars. We introduce technology only when it improves the driving experience – everything we bring in has to improve this. The excitement of the combustion engine is secondary. We look at everything about the car’s performance and, if it’s better with an electric powertrain, that’s what we will do.’
CvK: ‘With Regera, we were able to remove the transmission, so there are hardly any more components than you’d find in a series hybrid, and no frictional losses apart from the final drive.’
JL: ‘The evolution of the energy density of batteries is a key area of development. We’re seeing an improvement of five per cent in energy density for a given price point per year. The Speedtail’s battery has an energy density of 5.2kW per kilogramme, four times as dense as the P1’s battery.’
CvK: ‘Batteries are becoming around five per cent more energy-dense per year, and I don’t see any reason that trend should change. In five years or so it should be possible to make a battery car, with no combustion engine, that performs like the Regera. But we will continue to improve the combustion engine also. We foresee a shortage of battery cells, given how few are being produced today and how many EVs there may soon be…’
JL: ‘Solid-state [rather than lithium-ion] batteries can make a difference. The indicators for energy density are interesting, though it’s dicult to judge on the timeframe – different companies and suppliers have different views. We are working closely with these suppliers, and we are preparing to be ready to build a pure electric vehicle. If solid-state batteries arrive, and deliver on the promise, then they could be the step in the sports car world that gives the battery-electric powertrain the power density of a petrol engine. Direct comparisons depend on the evolution of the technology, but it could be that the first generation is a third lighter than what we have now, quickly getting to the point where it’s half the weight.’
CvK: ‘I think full solid-state batteries are quite far away. Dyson and some others were very confident on solid-state, then suddenly you read that they’re choosing something else. But while most of the development potential is in the batteries, there is still a lot left on the table with electric motors; making them more compact and more powerful, and using novel cooling methods. The trade is always cost, of course.’
JL: ‘The wins are smaller on the motors – we don’t need the technology steps we need from batteries. But there is more work to do here, as there is with inverters and the power electronics. Regeneration too is an important area. Brake feel and consistency are important for us – depending on the state of the battery, the feel of the pedal can vary. This is particularly important on a track, where consistency gives driver confidence – and when the driver loses confidence he loses laptime.’
‘In five years or so it should be possible to make a battery car, with no combustion engine, that performs like the Regera’