‘Electrification’ is a term that the auto industry has been using a lot of in recent years. Basically, it is a transition that will see internal combustion engines being replaced by electric motors. That transition began a few years ago with commitments by some to sell only ‘electrified’ vehicles by the end of this decade.

However, the transition will not see the switch to only electric motors occurring so fast. In the coming years, there will also be another partial electrification with hybrid powertrains which still use a combustion engine but with an electric motor also helping. The technology for this has been in mass production models since the late 1990s when Toyota introduced the Prius and is less costly than fully electric powertrains at this time.

Models with hybrid powertrains can therefore be offered at lower prices, making them more widely adopted and achieving at least partial reductions in CO₂ emissions. To wait for everyone to use a fully electric car will take time as economic circumstances in many regions may not make it possible for people to buy electric cars.

New-generation PureTech engine
This has led the Stellantis group to develop a new 48V HYBRID system which will be used in Peugeot models (3008 and 5008) initially. Revealed today, the 48V HYBRID system consists of a new-generation 136 bhp PureTech petrol engine, coupled with a new 6-speed dual-clutch electrified gearbox that includes an electric motor.

With the electric motor providing some of the propulsion, fuel consumption is said to be reduced by up to 15%, especially as the 3008 equipped with the HYBRID system can operate in urban conditions  more than 50% of the time in 100% zero-emission electric mode. Compared with a non-electric petrol engine with comparable features, the HYBRID powertrain offers average fuel savings of around 1 litre per 100 kms on a C-segment SUV.

Self-charging battery pack
In everyday driving, the two propulsion units work together or separately to optimise energy consumption. During strong acceleration, the electric engine provides additional torque to the petrol engine at low revs. When decelerating, the engine can cut off and the electric engine becomes a generator to recharge the 48V battery.

This means that the driver does not have to worry about looking for a charging station to recharge the battery pack. The range is therefore limited by the amount of fuel in the tank, just as in a car with just an engine.

All the parts that make up this new powertrain are located under the bonnet, except for the 48V battery pack, which is installed under the front left seat. The PureTech engine is of a new generation with a displacement of 1.2 litres from 3 cylinders. It has a variable geometry turbocharger which boosts output to 136 ps/230 Nm and operates on the Miller cycle for better combustion thermal efficiency.

Installed in the 3008 and 5008, the powertrain is coupled to a new electrified 6-speed dual clutch gearbox specially designed for hybrid systems. The gearbox housing also houses the electric motor,  inverter and ECU, optimising size and weight.

As with batteries in most current hybrid models, lithium-ion is as the storage medium and has high energy density. Its gross capacity is 898 Wh, with available capacity of 432 Wh. It is designed to maintain the same level of performance throughout the life of the vehicle and comes with an original 8-year/160,000 kms.

Two electric networks
For the 3008 and 5008, there are two embedded electric networks. A low voltage 12V network supplies the vehicle’s equipment while a high voltage 48V network supplies the hybrid system. Electricity is produced solely by the 48V e-motor, and a DC voltage converter is used to transfer part of the electricity produced to the car’s 12V network.

As part of its electrification process, this new HYBRID powertrain replaces the PureTech 130 EAT8. It will progressively be available in virtually every passenger model, with the 3008 and 5008 HYBRID models entering the European market in the second quarter of 2023.