Logan "Renault eco²" Concept
Logan "Renault eco²" Concept sets a new CO2 emissions record of just 71g/km at the 2007 Michelin-organised Challenge Bibendum.
More about Renault eco² appelation
Logan "Renault eco²" Concept
Thermal efficiency of powertrain => an 11 g reduction of CO2
Aerodynamics => 5 g reduction of CO2
Running gear => 3 g reduction of CO2
Energy-consuming components => 4 g reduction of CO2
A range of technical optimizations* and the 'eco' driving style of its driver enabled Logan Renault eco² Concept to cover the 172.20km route of the 2007 Challenge Bibendum on a mere 4.69 litres of diesel fuel. This performance works out at an average fuel consumption of 2.72 litres/100km and CO2 emissions of just 71 g/km!
An ambitious objective
The objective was to produce the most efficient vehicle on the market over a NEDC cycle, including vehicles using hybrid technology.
Bruno Cosatti, Head of Engineering, Prospective Studies and Innovation, explains: “Our objective was emissions lower than 100 g/km of CO2 (the volume production model emits 120 g/km)”.
What was the approach? “It consisted in applying relatively simple and affordable technologies to a volume production model and significantly reducing CO2 emissions,” says Bruno Cosatti.
Our work process consisted in applying “the theory of little streams that make big rivers,” says Bruno Cosatti. Numerous details were worked on in four areas closely linked to fuel consumption and thus CO2 emissions.
Action n°1 : Thermal efficiency of powertrain
=> an 11g reduction of CO2
- Engine power increased by more than 20% -> optimized gear-stepping => 4g reduction of CO2.
- New specification for combustion, pistons and injectors (development underway as part of studies led to comply with Euro 5 pollution standards) -> possibility to adjust settings for fuel consumption/pollution control balance => 5g reduction of CO2.
- Adjusted fit of powertrain components and use of adapted oils -> lower internal engine and gearbox friction => 2g reduction of CO2.
Action n°2 : Aerodynamics
=> 5g reduction of CO2
- Optimized sub-frame area (flexible blade under front bumper, fairing at the rear) -> less turbulence
- Adjusted air intake grille -> reduced cooling drag
- Wheel flaps -> reduced lateral turbulence
- Rear spoiler -> optimized overall vehicle drag
- Vortex generators: small aerodynamic components attached to vehicle roof used to direct airflow as close as possible to rear window -> lower vehicle drag
20% reduction of drag coefficient (Cd from 0.36 to 0.29), making Logan Renault eco² Concept one of the world’s most aerodynamic notchback sedans.
Action n°3 : Running gear
=> 3g reduction of CO2
- Use of Michelin Energy Saver 185/65R15 tires with low rolling resistance => 2g reduction of CO2.
- Low-friction rear axle bearings => 1g reduction of CO2.
- Optimized adjustment of toe-in and camber angles -> optimized wheel-road contact
Action n°4 : Energy-consuming components
=> 4g reduction of CO2
- Battery charge with broader operating range than usual standards
-> less frequent charge and less energy consumption => 2g reduction of CO2.
- Vehicle with minimum equipment, in particular a manual steering model.
A gearshift indicator
Alongside these optimized items, the Logan Renault eco² Concept dashboard is fitted with a gearshift indicator. If drivers fully use the indicator, CO2 emissions can be reduced to less than the homologated 97 g/km. Bruno Cosatti explains: “ In terms of fuel consumption and CO2 emissions, the car-driver relationship is essential, and optimizing vehicle use conditions and operating ranges, especially those of the powertrain, is just as important as the technical improvements made elsewhere.”
> Find out more about the Bibendum Challenge
