LOGAN 'RENAULT ECO²' CONCEPT ACHIEVES RECORD CO2 EMISSIONS OF 71G/KM AT 2007 CHALLENGE BIBENDUM, SHANGHAI
The Renault Logan saloon is already a smash-hit around the world. Now the high-selling model has another target in its sights, following an impressive set of fuel economy and emissions results at this year's Challenge Bibendum in China, held this week.
The exceptional success of the Logan Renault 'eco² Concept, an experimental car conceived for the Michelin-organised event in Shanghai, adds weight to Renault's belief that it is possible to combine ecology and economy, affordably and without detracting from performance.
A range of technical enhancements and the eco-driving style of its driver enabled the Logan Renault eco² Concept to cover the 172.2km route of the 2007 Challenge
Bibendum on a mere 4.69 litres of *B30 biodiesel. This gave an average fuel consumption of 2.72 litres per 100km and CO2 emissions of just 71g/km.
During NEDC combined cycle homologation tests for the vehicle, it achieved a result of 97g CO2/km, equivalent to fuel consumption of 3.8 litres/100km.
After the Challenge, competing vehicles were judged on the following criteria: an acceleration test, a slalom test, noise emissions and a regularity run. Out of a total field of 74 vehicles, the Logan Renault eco² Concept finished an impressive second. This excellent result demonstrates its ecological credentials were not obtained to the detriment of performance which very much remains a feature of the car.
The Renault eco² symbol illustrates the brand's commitment to offering a line-up of ecological, economical vehicles that show measurable results throughout their life cycles, as well as new technologies at prices which most customers can afford.
To qualify for the Renault eco² symbol, vehicles must comply with all three of the criteria listed below:
- They must emit less than 140g of CO2/km or else run on biofuel,
- They must be manufactured in an ISO 14001-certified factory,
- They must be 95% end-of-life reusable, and at least 5% of the plastics used in their production must be sourced from recycling.
Today, 40% of the versions in the Renault range qualify.
Not only is the Logan Renault eco² Concept extremely economical, it is also ecological and complies with all three of the criteria that count towards the eco² symbol. It was manufactured at the Pitesti plant in Romania, which has been ISO 14001-certified since 2005, while the finished vehicle contains 8.3% of recycled plastics and is 95%-reusable by weight. Finally, special attention has been paid to bringing its CO2 emissions below the 100g/km threshold.
Powered by a 1.5 dCi 85hp engine running on B30 biofuel, it incorporates a variety of technical enhancements and innovations, all of which are paths for future vehicle development at Renault.
This is based on the 1.5 dCi (85hp) engine launched at the end of 2007 and homologated at 120g CO2/km. The final drive ratio has been lengthened 8% to reduce fuel consumption while ensuring a level of mid-range acceleration that is suitable for ordinary use. This enhancement gave a saving of 4g CO2/km. The injection system has also been re-calibrated by introducing seven-hole nozzles (instead of five as is the case with production models) and widening the piston bowl for enhanced fuel spray and combustion. This modification produced a further saving of 5g of CO2/km. Finally, by optimising the balance between certain moving parts and using low-viscosity lubricants (5W20 plus additives instead of the standard 5W30), internal engine friction has been reduced. The gear oil is also less viscous. This work helped cut CO2 emissions by a further 2g/km.
Powertrain adjustments led to a total CO2 emissions gain of 11g/km.
Aerodynamic performance was maximised by drawing on fundamental research findings in aerodynamics and by revisiting the test work carried out in the course of Logan's development. Analysis of the most cost-effective solutions identified six points that together produced significant aerodynamic gains.
- A flexible splitter under the front bumper to reduce underbody turbulence combined with a spare-wheel fairing to optimise the flow of air underneath the car.
- The front air intakes were modified to reduce the drag caused by air-cooling airflow.
- Wheel fairings to reduce lateral turbulence
- A rear lip spoiler to reduce the vehicle's overall drag performance
- VORTEX generators (small, drag-reducing, roof-mounted features that channel airflow to reduce rear drag, a particularly effective solution on three-box cars
- A slightly lower ride-height.
Altogether, the drag co-efficient was cut by some 20%, from 0.36 for the production Logan to 0.29, a score that makes Logan Renault eco² Concept one of the most aerodynamically efficient three-box saloons. This gave a CO2 gain of 5g/km.
The aim was to reduce fuel-hungry mechanical friction with solutions that are more realistic, such as:
- Logan Renault eco² Concept is equipped with new Michelin Energy Saver 185/65R15 low rolling resistance tyres. This brought a CO2 gain of 2g/km (NEDC homologation cycle).
- The use of low-friction rear bearings led to an emission gain of around 1g of CO2/km. The camber and toe settings were also optimised.
Work on the running gear helped to achieve CO2 emission gains of 3g/km.
Lower energy needs:
The active control alternator ensures that the battery is charged only as required (12.8V instead of 13.5V). The battery consequently doesn't have to be charged as frequently, which leads to lower fuel consumption. Measures taken to reduce the effect of energy-hungry parts helped reduce CO2 emissions by 4g/km.
The sum of all the work that went into Logan Renault eco² Concept achieved record low CO2 emissions of just 97g/km (NEDC combined cycle) equivalent to fuel consumption of 3.8 litres/100km. Furthermore, the extra-urban phase of the NEDC driving cycle returned UTAC-homologated fuel consumption of just 3.4 litres/100km, equivalent to CO2 emissions of 88g/km.
Driving style can also play a significant role when it comes to curbing fuel consumption and CO2 emissions. The dashboard of Logan eco² Concept features a gearshift indicator that enables drivers to make an active contribution to the optimization of fuel consumption. By taking full advantage of this aid, drivers can bring Logan Renault eco² Concept's CO2 emissions performance below the homologated score of 97g/km.
These results are remarkable for the five-seater family saloon category. Logan eco² Concept reaffirms Renault's determination to demonstrate that ecology and affordability can go hand-in-hand and asserts its conviction that the most effective environmentally friendly techniques are those that are readily accessible to the vast majority of motorists.
Depending on the country of sale, Logan is commercialised under the Dacia and Renault brands. The Dacia brand comes to the UK in early 2009.