Lexus claims the new system offers an enhanced driving experience with increased performance and efficiency through a new multi-stage hybrid system that marries elements of a traditional full hybrid powertrain – including a 3.5-litre V6 petrol engine, electric motor and lithium-ion battery pack – to a four-speed automatic gearbox mounted at the rear of the hybrid transmission.
“The previous hybrid system was a very capable system that could propel a GS450h from 0-250km/h at mind-blowing speed. So, the new system is essentially the same basic unit that we have – we’ve got a V6 engine, but it’s been revised with a little more power and better efficiency, but it’s still using the 3.5-litre V6.
"Attached to that, we’ve got two motor generators and a power-split device, and up to that point there’s very little difference to what we already have," according to Lexus Europe’s Senior Technical Trainer, Stefan Ramaekers.
“The real change is with this new multi-stage device – four-stage shift. By using a shifting device behind the entire hybrid system, we allow the engine to reach its maximum potential at just above 50km/h rather than the 130km/h with the previous system – so a lot more power available at lower speeds.
“The end result is that this car develops total outputs of 220kW and 348Nm and will accelerate from 0-100km/h in five seconds flat," he added.
Lexus also claims its latest hybrid system spells the end of that rubber band feeling so common with hybrid vehicles.
“This new multi-stage system no longer has a disconnect between engine rpm and vehicle speed. Now, we actually link it by mimicking the 10 gear ratios, as we have on the V8, to get that linear shift feeling we now have.”
The LC500h also marks the first-time Lexus has used lithium-ion battery technology over nickel-metal-hydride, due to its light weight and compact properties.
“For the LC500h we needed go a step further in battery technology, as the multi-stage shifting device adds weight, so we needed to compensate. And lithium-ion batteries are really good at harvesting energy versus a low volume and a low weight.
“It doesn’t just do that. Lithium-ion is also really good at absorbing and dissipating energy, so it packs much more punch than nickel-metal-hydride, which accounts for the extra 45kW we get when the battery is at full load,” Ramaekers told CarAdvice.
Another first for a Lexus hybrid is the addition of an M mode to select and hold gears manually, using the paddle-shifters mounted behind the steering wheel.
Coordination between the power split device and the gear shifting mechanism allows the gear shift to start instantaneously with the computer receiving the signal from the paddle-shift, for quick response.
There are also six driving modes to choose from including Sports and Sports Plus, but what’s the difference?
“In Sports mode, it’s all about powertrain – the entire powertrain will adapt to a more sports setting – higher output, quicker response and faster shifting.
“If you move to Sports S Plus, it is the entire car that changes behaviour – the steering get lets less power assistance, so it’s more responsive and the variable suspension will be firmer for some proper performance driving,” Ramaekers concluded.
For more on the new Lexus LC, including CarAdvice's first drive review, see our links below.