Renault Group

The origins of Renault E-TECH

episode 5

200 hp and lower consumption: the challenge for this new generation

Renault developed its trailblazing hybrid E-TECH powertrain by leveraging its expertise in electric vehicles and experience in Formula 1, and adding its engineering, development and control teams’ enthusiasm and passion. It introduced the first generation, delivering 140 hp, in 2020. The second, unleashing 200 hp and powering Austral, Espace and Rafale, reached the market in 2022 and 2023. The upgrade included extensive optimisation and, most importantly, a completely new, ultra-efficient 3-cylinder internal-combustion engine. This E-TECH full hybrid 200 hp version had been in the development pipeline since 2018.
The first-generation E-TECH engine has made a major contribution to Arkana's commercial success
The feedback from the press after test-driving Clio and Captur E-TECH hybrids in 2020 was more than encouraging, and this game-changing powertrain was clearly off to a great start. It was more efficient, the difference in fuel consumption was real and the price difference with a similar petrol engine was reasonable. Arkana, further up the scale, confirmed all this in 2021: the hybrid version promptly outsold the two petrol ones and accounted for about 60% of total sales in 2022. For at least three good reasons: The car invariably starts in full-electric mode, and customers could drive in full-electric mode 80% of the time in cities and consumed up to 40% less fuel.

The catch was that Renault planned to market more imposing, status-symbol cars – Austral in 2022, Espace in 2023 and Rafale in 2024 – and 140 or 145 hp under their bonnets was not enough. In any event, Renault’s CEO Luca de Meo unambiguously and unapologetically stated that “We want to make the best hybrid powertrain in the world”, and tasked Gilles le Borgne (then Renault’s EVP Engineering) and Philippe Brunet (then SVP Powertrains) with delivering it using the first generation’s technology. They naturally sat down with the teams that had developed the E-TECH powertrain – who were already aware of this need and figuring out how to satisfy it.

Rafale to benefit from second-generation E-TECH engine, boosted to 200 hp
We had already found the new ICE engine to replace the naturally-aspirated 1.6 engine of the 140 hp first-generation, and we knew what levers we could pull to further optimise power, driver comfort and efficiency. We were facing solidly established competitors and many new players and gave ourselves a year to optimise the electric motor’s performance, fine-tune the whole system, reduce consumption, shorten ignition time and smoothen gear shifts, among other things,
Nicolas Fremau
Powertrain and Hybrid Expert who masterminded E-TECH with his wingmen Ahmed Ketfi-Cherif and Antoine Vignon
It was far from simple. And couldn’t be more exciting for them!

200 HP and a lower consumption: the challenge for E-TECH M


The main component they had to replace with a more modern, more powerful and more efficient one was the ICE engine. They retired the first-generation four-cylinders naturally-aspirated ICE engine – which had worthily fulfilled its purpose but was only still there because it was the best available trade-off in 2016 – and got to work on an engine that would be, in Francis Boutonnet’s words, “perfect for the job.
The new E-TECH 200 hp powertrain based on the HR12 ICE engine
Francis, who was Project Manager for HR family petrol engines at Renault Group and the Alliance, had worked on the four-cylinder (1.3 TCe) engine developed with Daimler and launched by Renault in 2018.
Developing the 1.3 TCe engine put us back in the technical race to build a high-efficiency petrol engine, but we had to take one step further,” he remembers. “At the time, in 2015-2016, we could see that regulation on the horizon would push diesel to the sidelines. We needed a new standard-setting petrol engine that would rank among the most energy-efficient on the market. Which is what we had done with the 1.5 dCi then 1.6 and 2.0 dCi diesel engines a few years prior.
Francis Boutonnet
Project Manager
This new petrol engine needed all the latest and greatest technology to improve energy efficiency. But the engineers also had to look beyond that, at the requirements that future standards – notably Euro 7 – would usher in. To solve that brainteaser, Francis Boutonnet had to work on several solutions:

At the time, all the petrol engines on the market carried surplus fuel to help keep their stochiometric mixture right at high speeds – in other words to keep the air-to-fuel ratio right in the combustion chamber, in order to avoid overheating. But we could sense that, sooner or later, this would be a problem from a regulatory standpoint. So we needed an engine that would keep the right stoichiometry however hard you pushed it. We were also certain that, to optimise efficiency, it needed the Miller cycle and a system to recirculate burnt gases with an EGR valve.”

Francis Boutonnet
Project manager

Nissan had already fitted a petrol engine with an EGR valve – which cuts NOx emissions and improves efficiency by routing some of the exhaust gas back to the cylinders instead of releasing it. But Francis and his teams wanted to take one step further than their Japanese colleagues: “We were aiming for a 20% recirculation rate. So we had to shorten the circuit between the turbocharger and the air intake, and add a water-to-air intercooler (CAC), which wasn’t common on a petrol engine at the time.

Likewise, designing a Miller cycle engine involves tweaking a number of mechanisms. In this system, the intake valves close before the piston reaches its bottom-most position, to optimise output. As a result, the air-fuel mixture spends more time in the combustion chamber before it reaches the combustion spark. This for instance involved reworking the aerodynamics in the intake ducts and combustion chamber, which in turn entailed “running many simulations then multiple tests, in-house and with partners, on a single-cylinder engine before moving on to a multi-cylinder engine”, Francis Boutonnet remembers.
It was on board the Austral prototypes that this powertrain was developed.
lorem ipsum
The 3-cylinder 1.2-litre petrol engine in the E-TECH M powertrain has a better specific fuel consumption curve than a 4-cylinder diesel engine of equivalent power

Speaking of cylinders, how many would this new ultra-efficient petrol engine have? Francis Boutonnet’s answer helps to understand the link with the E-TECH 200 hp engine: “We started developing this engine to use it ‘solo’, but we also reckoned it would work perfectly well in a hybrid powertrain like E-TECH. As long as we kept it compact enough to fit in all the engine compartments without making the powertrain heavier. So we went for a 3-cylinder architecture. As it happened, at constant capacity – in this case 1,200 cm3, it was actually more energy-efficient than a 4-cylinder architecture.

They also had to shave some of cylinder head’s height to avoid shortening piston stroke (which again enhances energy efficiency), add an optimised 350 bar injection system, rearchitect the catalytic converter to treat emissions more effectively, and keep on fine-tuning everything they could to ease friction and thus consumption. But this 1.2 TCe engine was really the one they needed for the new hybrid E-TECH powertrain generation.


Changing the other components in the hybrid E-TECH powertrain was out of the question but our specialists nevertheless scrutinised them one by one, principally to step up the electric motor’s performance, and thus overall power, while further optimising efficiency.
We started equipping this ‘simple’ hybrid powertrain with the 400 V architecture from the plug-in hybrid powertrain we were using in Captur and Mégane. The first E-TECH generation only had a 230 V architecture. We put in a 2 kWh battery instead of the 1.2 kWh battery. That extra voltage increased the main electric motor’s power rating from 35 kW to 50 kW (48 hp to 68 hp).
Ahmed Ketfi-Cherif
Control Expert working on this hybrid E-TECH powertrain

Nicolas Fremau continues, “We had to strengthen the dog clutch gearbox so that it could handle the higher power and torque from the engine and main motor. While we were at it, we enabled the fifth gear (which was built into but not used in the first E-TECH version). To do that, we simply tweaked the gear ratios.

These two smart and simple solutions worked well in the circumstances, as time and funding were tight. The team had come up with several clever ideas so far and had a few more in store. Especially one that Antoine Vignon, the engineer behind the novel gearbox, thought up and later patented: removing one of the sprockets moving the second electric motor (the high-voltage starter generator or HSG).
That optimised output throughout the mechanism, reducing emissions by 0.5 grammes of CO2 per km. And small gains, at the end of the day, make a big difference.

Lastly, the new hybrid E-TECH 200 hp powertrain benefited from software upgrades and electronic enhancements that had already been used on the original 140 hp version. For example starting the engine with the HSG instead of a cylinder – which works better on cold mornings. Also noteworthily, they used the HSG – again – to adjust torque and thereby avoid turning off (and then having to turn back on) the ICE engine while shifting gears. “All that lowers consumption, and wipes out a further 2.7 grammes of CO2 per km!”, Nicolas Fremau adds.


The new 200 hp version of Renault’s hybrid E-TECH powertrain was ready to power Austral in 2022 and Espace in 2023. So did Nicolas Fremau, Ahmed Ketfi-Cherif, Antoine Vignon and their teammates catch a breath? Not yet: they had another variant, with even more power and a different architecture in the pipeline…