282mpg with 22g/km CO2 – we drive Renault’s super-eco breakthrough EOLAB prototype.
Sean Carson | October 2014
Standing in the late afternoon autumn sun bathing the hidden industry testing facility located just outside of Paris, project director for Renault’s EOLAB eco concept Laurent Taupin goes all Yoda on me:
“The EOLAB is not the Clio of the future. But it is also the Clio of the future.” I get what he means though.
While the EOLAB is Clio-sized – it’s as long and as wide as the current French supermini, but 50mm lower – it doesn’t just represent the next Clio replacement. It’s showcasing around 100 “innovation building blocks” that will help improve efficiency across the whole Renault range.
The working prototype version stood in front of us shares its overall look with the suicide and beetle-wing-doored concept that stood pride of place on Renault Paris Motor Show stand just one week ago. Unfortunately, those futuristic portals granting entry to the EOLAB don’t make it here, and neither does the swish concept cabin.
It’s still advanced inside, but think more Renault Zoe than Renault Zarg. No, this is not about looks, the EOLAB is a working testbed for technology that will underpin all Renaults of the future.
Sipping fuel at a rate of 282mpg and coughing just 22g/km CO2 into the atmosphere, the innovations in this Renault are real-world relevant – cheap and with plenty of production potential.
What’s the Renault EOLAB prototype like to drive?
Unremarkable, which is actually the biggest compliment you can pay the EOLAB prototype. Sure, it’s a bit rough around the edges in places, and refinement for a production application needs to be addressed, but given this car is just a means of testing the tech, Taupin and his team’s approach has been validated by the results.
There’s a 75hp 1.0-litre petrol engine from the Renault Twingo under the fixed bonnet linked to a 54hp electric motor, which together drive through a new clutchless three-speed gearbox. This is quite a complicated piece of kit.
The car always starts off in all-electric ZE mode, with the electric motor driving the first gear. If there’s not enough volts available, the petrol engine can charge the battery to top it up.
The electric motor can also drive the second gear on its own, while the petrol engine delivers its power through the third gear. This means there are nine different combinations of gears using petrol, electric or a mix of the two power sources, sufficient to cover a real-world speed range, says Renault.
It’s a bit clunky currently, and there are a few noticeable pauses and hesitations as gears engage and disengage (what else would you expect from an early prototype?), but the fundamentals are sound and allow integration of the two power units to maximise efficiency.
We’re sure that when – not if – this technology gets the green light it’ll be properly developed and refined.
The target was to match the performance of a TCe 120 Clio, and Renault has achieved that – 0-62 takes the same 9.0 seconds. From rest it feels punchy, with the electric motor whisking you away on a silent wave of torque.
It’ll travel up to 41 miles on battery power alone, or at speeds up to 75mph. When the petrol engine kicks in there’s a whir from the starter and a thrum as the triple fires. It adds extra performance for higher speed cruising, but importantly, extra range as well.
There are two modes for the EOLAB’s powertrain. The first – “Weekday” mode – favours electric propulsion making it more efficient on the school run or the commute. The second – “Weekend” mode – combines petrol and electric motors for extended range and more poke.
The steering feels like a Clio – light and effortless, helped by the super-skinny 145-section tyres – and the brakes feel conventional.
Like many hybrids, it uses the motor in reverse to slow the car, acting as a generator to charge the batteries. If you stamp on the left-hand pedal (clutchless, remember…) the downsized and therefore lighter discs and pads will come into play.
What technical innovations does the Renault EOLAB prototype feature?
The EOLAB was born out of a French government challenge to its carmakers, asking if any of them could achieve fuel consumption of 141mpg. Renault went twice as far, trumping Peugeot-Citroen with its 282mpg EOLAB.
It’s done so by focusing on three pillars of development: aerodynamics, weight reduction and powertrain improvements.
Incredibly, it’s 30% more aerodynamic than the current Clio. Along with the lower roofline creating that swoopy shape, the EOLAB features active aerodynamics.
There’s a spoiler at the front and flaps at the back that open and close to reduce drag above 70kph (around 44mph). These combine with an air suspension system that can raise or lower the car on the move to further reduce any brick-like aero properties.
Parked up, the EOLAB sits in its highest mode to help entry and exit to the cabin. Between five and 70kph it lowers by 25mm, and above this it drops by another 25mm, helping to reduce its thirst and improve high-speed stability. There are active flaps on the wheels to reduce drag, too.
On top of its slipperiness, Renault has saved a whopping 400kg over a regular Clio. This means it only needs that small engine and a modest battery pack to power it around – even if the lithium-ion cells do add 145kg back in.
Renault saved 130kg from the body, 90kg on trim and equipment, 70kg on suspension and 90kg on the powertrain and peripherals.
Clever innovations come in the form of a 2.6kg saving due to thinner glass, 4.5kg from a magnesium roof, 14.5kg from the brake system, and 12kg thanks to smaller, lighter seats. Extensive use of aluminium and plastic composites, as well as interior plastics with bubbles in (just like Aero chocolate…) to make them lighter also help keep the kerb weight under a tonne.
Finally, the petrol triple has been tilted by 49 degrees to maximise cabin space (despite the lower roofline, there’s still as much space as a Clio inside) and maintain pedestrian impact protection, while the electric motor and gearbox have been constructed to maximise their lightweight properties, undercutting a conventional auto or dual-clutch transmission when it comes to mass.
The engine is also linked to a clever 11-inch touchscreen that gives real-time efficiency info on what’s consuming energy (importantly, not just liquid fuel). The pentagon diagram’s five points represent climate control, the tyres, aerodynamics, gradient, and acceleration and braking.
Each ‘limb’ of the diagram will spike when that particular facet is consuming more energy, with the feedback helping to coach drivers on how to be more efficient at the wheel.
MR verdict: 2014 Renault EOLAB prototype
The EOLAB is Renault’s future – a technological showcase on how it will improve efficiency across its model range. The petrol-electric setup is nothing new, but the way it’s managed through the gearbox is.
Best of all, using simple concepts like weight-saving and aerodynamic improvements, these features really aren’t a long way off. By 2022 we’ll see 80-90% of technology on the EOLAB filter down to Renault’s road cars at an affordable level.
The innovations work today, and with a few refinements 282mpg with 22g/km at a cost that won’t break the bank will be extremely appealing.
Specification: Renault EOALAB prototype
Engine: 1.0-litre three-cylinder petrol, electric motor
Gearbox: three-speed clutchless automated manual with nine ratio combinations
Power: 75hp petrol engine, 54hp electric motor – 129hp total
Torque: 70lb ft petrol engine, 147lb ft electric motor – 217lb ft total
0-62mph: 9.0 seconds
Top speed: 81mph (limited for prototype)