At the cutting edge of hybridisation

Hybridisation with our E-Tech gem

Renault Group is well-known for its expertise in electric vehicles, but the company also boasts another highly coveted asset: its E-Tech technology, a true gem for hybridising the internal combustion engines in its range. This unparalleled technology enables the Group to offer a range of hybrid vehicles with impressive performances.

E-Tech is, above all, an intelligent and high-performing gearbox. Its performance is notably enhanced by optimizing friction points, which are essential sources of efficiency loss. The result: an engine efficiency increase of 20% compared to an equivalent conventional system!

So, how does it work?

More than 150 patents filed.

The exceptional performance is enabled by a series of technological breakthroughs, with E-Tech technology being the subject of over 150 patents. These innovations span the design of the gearbox, shifting modes, and software enhancements.

To name a few, the traditional clutch used for starting is replaced by an electric motor that initiates vehicle movement, with the petrol engine engaging only later. Another technological breakthrough is the choice of a more effective dog clutch system, using the torque of a second electric starter-generator to adjust speeds and engage gears.

Additionally, there's the ERP, Energy Road Planner, which optimizes energy consumption by planning the desired route via GPS. The system adjusts the use of the drivetrain (100% electric, 100% thermal, or hybrid) to achieve the best consumption for the journey, all seamlessly for the customer.

In our E-Tech technology, the electric traction motor is connected to a 2-speed gearbox. The petrol engine, on the other hand, has a 4-speed gearbox, and together they enable operation with at least 15 different driving modes.

These innovations, among others, were initially used in 2020 to hybridise an existing engine, leading to the commercialization of the first generation of our hybrid powertrains, the E-Tech Full Hybrid 145 hp, on the Renault Clio, Renault Captur, and Renault Arkana. This first generation demonstrated remarkable performance: 15% more efficient than a diesel engine and even 25% more efficient compared to a petrol engine. With best-in-class consumption and CO2 emission levels (Clio HEV 145 hp: 4,3l/100km et 96 g CO2/km WLTP and an average fuel consumption observed in customer use of 5.3 litres/100 km).

A second generation even more efficient.

We went even further with the second generation, developing an engine specifically designed for this hybridisation. The results are remarkable, with a 7% efficiency gain over the first generation.

This is a 1.2-liter turbocharged 3-cylinder petrol engine delivering 96 kW and 205 Nm of torque. It is paired with a more powerful and torque-rich electric motor (50 kW and 205 Nm) and a larger capacity lithium-ion battery (2 kWh / 400V). It operates on the Miller cycle* and is designed to reduce frictions thanks to the absence of drive belts and an electric water pump. Its efficiency is 42%, an impressive level for a production engine.

The combined power of the petrol and electric motors reaches 146 kW, or 200 hp, with the best consumption/performance ratio on the market. For example, the average consumption on an Austral (C SUV) is 4,6/100km et 104 g CO2/km WLTP and an average fuel consumption observed in customer use of 6.3 litres/100 km.

The adventure keeps going.

The story continues today with a high-performance, 300-horsepower PHEV version for the 4-wheel-drive model of our flagship, the Renault Rafale. Thanks to optimised energy management between the different engines, standardised consumption in the WLTP cycle is 0.7 litres / 100 km (15 g of CO2/km) with a full battery and 5.8 litres / 100 km (132 g of CO2/km) with an empty battery!

To achieve this market-leading result, we first optimized the E-Tech hybrid powertrain, which underwent significant evolution to increase power. We added a third electric motor at the rear of the vehicle to enable all-wheel drive. Finally, a plug-in hybrid battery integrates 20 kWh of energy! This allows for nearly all daily trips to be completed in 100% electric mode.

The adventure keeps going, and so do our technological advancements!

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*Unlike a traditional four-stroke internal combustion engine, where the compression stroke is equal to the expansion stroke, the Miller cycle adjusts the intake time to neutralize a portion of the cylinder volume during the compression phase, while keeping this volume available for the expansion phase. This makes the compression stroke effectively shorter than the expansion stroke. The major advantage of the Miller cycle is achieving a higher thermodynamic efficiency.