The Technology Behind the Peugeot 508 RXH
For many years, hybrid technology in cars was limited to electric-petrol crossovers. It wasn’t until Peugeot introduced the HYbrid4 3008 in 2012 that the world first saw a mass-production electric-diesel hybrid. This technology combines the better running costs of diesel cars with the improved fuel efficiency and environmental benefits offered by electric vehicles.
With the release of the HYbrid4 3008 and the 508 RXH, Peugeot showed itself to be an innovator in the field of green vehicles. But if the crossover of diesel and electric technology used by cars is so beneficial, why did it take so long to produce? And why didn’t other car companies attempt to produce similar technologies? We’ll attempt to answer these questions by taking a closer look at the HYbrid4 technology used in the 508 RXH.
Part of the reason that no other car company had mass-produced anything like the HYbrid4 systems used in the 508 RXH is that its creation brought together a number of technologies developed in-house by Peugeot. These technologies were key to HYbrid4′s development, and included an electronically-controlled sequential manual gearbox and ‘Stop & Start’ technology – which automatically stops the car’s engine when it’s stationary to save on fuel. HYbrid4 also incorporates the best of diesel engine and electric motor manufacturing prowess.
The fact that it is possible to combine these technologies – and the fact that cars have been developed shows, it could be argued, the radical progress that has been made with hybrid vehicles in recent years.
In basic terms, a HYbrid4 vehicle incorporates an electric motor and a diesel engine which either work together to drive the vehicle, or work independently. When the electric motor is engaged on its own (this is known as ZEV, or ‘zero-emissions vehicle’ mode) it provides an emissions-free driving experience which is ideally used when driving the 508 RXH around towns and cities.
In Auto mode, the diesel motor – placed at the front of the car – drives the wheels when the car is driven at higher speeds, such as on motorways and main roads. The electric motor takes over when the car starts, when it decelerates and when it is driving at low speeds. This changeover in power sources is handled by an on-board computer system, which automatically deduces the ideal power usage for maximum driving efficiency. The batteries that power the electric motor are kept charged, because the car’s kinetic energy is captured and used to recharge the batteries when the brakes are applied – this is a process known as regenerative braking.
The 508 RXH can operate in four modes, which are chosen by the driver via a selection dial. As well as the aforementioned Auto and ZEV modes, drivers can choose from 4WD mode – which engages both the engine and the motor, making the 508 RXH into a four-wheel drive vehicle – and Sport mode, which also uses both power sources, but to boost performance, rather than simply to improve grip in extreme weather conditions.
The 3008 HYbrid4 and the 508 RXH both make use of Peugeot’s HYbrid4 diesel-electric hybrid technology. This article looks at this revolutionary green car technology in detail.