| 2014-09-17 | 0 Comments

Scheduled to have its World Premiere at the 2014 Paris Motor Show, Renault EOLAB is an environmental prototype with nearly 100 technological innovations designed to deliver ultra-low fuel consumption, of one litre per one hundred kilometres!, whilst maintaining established B-segment levels of performance, practicality and affordability.

Renault_Eolab_1The prototype’s exceptional fuel economy is the fruit of work on three main fronts: refined aerodynamics, weight saving and Z.E. Hybrid technology (petrol/electricity):
– The car’s shape was designed to slice through air efficiently, while movable devices such as an active spoiler and lateral vanes perform the same way as ailerons.
– A weight saving programme brought the car’s mass down 400 kg, thanks in particular to a multi-material body shell combining steel, aluminium and composites, as well as a remarkable magnesium roof that tips the scales at barely 4 kg.
– Z.E. Hybrid technology: this new, compact and affordable hybrid power unit combines ultra-low fuel consumption with zero-emission mobility for journeys of less than 60 km and at speeds of up to 120 kph.

Renault_Eolab_7EOLAB’s ride height is variable thanks to the use of active air suspension. The four dampers can be raised or lowered by 25 mm in relation to the default setting. When the car is parked, the suspension switches to its highest position in order to facilitate entry. As the vehicle begins to move, the suspension resumes its default setting (i.e. it lowers by 25 mm) at speeds of between 5 and 70 kph in order to limit the amount of air that passes underneath it. For the same reason, the ride height is lowered by a further 25 mm at speeds in excess of 70 kph. At the same time, the front bumper equipped with an active spoiler, lowers by 10 cm at speeds in excess of 70 kph in order to restrict airflow beneath the car.

Renault_Eolab_5Another mobile feature of the aerodynamic package is the 40 cm x 10 cm vertically-positioned flaps on the rear bumper, rearward of the rear wheels. At speeds in excess of 70 kph, these flaps open by 6 cm in order to ensure that as much of the airflow as possible stays attached to the vehicle as it moves forward. Without this solution, passing air has a tendency to become detached from the vehicle’s sides too early after passing the rear wheels and this has a negative effect on drag.

Renault_Eolab_8The teams that worked on EOLAB took a close look at its wheels, too. In a perfect aerodynamic world, the rims would be covered and smooth. This is rarely the case, however, essentially for design- and brake cooling-related reasons. An ingenious system was consequently designed whereby the rims are covered whenever the brakes do not need to be cooled, thereby reconciling design and aerodynamic efficiency considerations. The system is controlled by a temperature sensor built into the rims.

Renault_Eolab_9To further perfect EOLAB’s aerodynamic performance, it is fitted with particularly narrow, 145 mm-wide tyres. That’s 40 mm narrower than the smallest tyres available for the Clio IV. Michelin and Renault’s designers worked on the tread pattern to give a visual impression of width, while the sidewalls were designed to exude an impression of light weight. At the same time, tyre supplier Michelin optimised the casing and tread to minimise rolling resistance while maintaining excellent levels of safety and performance.

Renault_Eolab_4In the case of the EOLAB prototype, the ICE part of the powertrain takes the form of a small three-cylinder 999 cc petrol engine with a power output of 57 kW (75 hp) and peak torque of 95 Nm. It is mated to a highly innovative clutch-less transmission based on a compact and economical three-speed gearbox. The chief feature of the concept lies in the clutch casing which houses a permanent magnet electric motor (axial flux discoid motor in the case of the prototype). This motor is compact and economical and covers the need for the availability of extra torque since it is capable of instantly delivering peak power of 50 kW and 200 Nm of torque.

Renault_Eolab_2Fed by a 6.7 kWh battery, it is sufficiently big to power the car under electrical power. Here again, the war waged on the weight of the body shell made a great deal of sense inasmuch as a lighter car needs less energy to be moved forward. As a consequence, the battery can be both smaller and less expensive.

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