More "eco" in new performance tyres
Tests carried out on and off the Algarve racetrack to demonstrate how the new ContiEcoContact 5 and ContiSportContact 5 series for cars have raised the performance crossbar compared to their respective predecessors
by Mino de Rigo
The common denominator of both new products is the use of construction techniques and new compounds, with 15 to 20 different types of compounds for different areas of the tyre.
“The ever-increasing requests by car manufacturers for performance tyres that will reduce rolling resistance have been met with new optimized products”. And they are the new ContiEcoContact 5 and ContiSportContact 5 that Nikolai Setzer, head of the car and light transport tyre division at Continental, presented to the international press at the launch in Portimão, southern Portugal, emphasizing how the claim of a brand that has always been synonymous with safety has now been strengthened by combining imperative energy efficiency with braking performance on the wet”, two of the three key parameters on the new European label. “This is how” – Setzer added – “EcoContact 5 reduces rolling resistance by 20% compared to its predecessor EcoContact 3, and SportContact 5 can also boast over 10% improvement compared to the previous model”. If the first belongs to the segment of the so-called eco-performance tyres, available for rims from 14” to 17” and speeds of up to 300 km/h, then the second belongs to UHP tyres and, with 23 sizes from 16” to 20” for cars and another 7 from 18” to 20” for SUVs, it completes the range renewed last year with the introduction of the supersporty ContiSportContact 5P. The common denominator of both new products is the use of construction techniques and new compounds, with 15 to 20 different types of compounds for different areas of the tyre.
Less weight, more durability
Focus on profile configuration and the tread pattern demanded of the EcoContact 5 as an additional and indispensable contribution to combining conflicting parameters by definition, energy efficiency and handling on the one hand, rolling resistance and braking on wet roads on the other. “The sum of the improvements” – head of development Burkhard Wies explained – “was achieved by work on reducing rubber hysteresis, minimizing sidewall flexion and reducing carcass weight, which has given the ContiEcoContact 5 higher overall performance. The new tyre, which on average weighs one kilo less than its predecessor, reduces braking distances on the wet by 10%, reduces fuel consumption by about 3% and even increases mileage by 12%”. This result is the outcome of work on the tyre profile which is ultra-flat with a kind of microsiping, and the new compound, which will reduce friction (by containing slipping, tangential stress, and giving even radial tension) and wear by compound abrasion, respectively. Less waste of energy also means lower CO2 emissions.
The ContiSportContact 5 is also accredited with lower emissions and more mileage (13%), and it outclasses the previous model if, as the comparison graph shows, it is true that it is superior not only for rolling resistance but also with regard to handling, braking on wet, resistance to aquaplaning and containment of noise.
Modular and adaptive technologies
“We have always made ample use of technologies that identify four distinct areas of the tyre (load, grip, flexion and rigidity), and applied the most suitable solutions to each one”, emphasized project leader Markus Fischer. A modular approach which, to optimize grip when cornering, has used a tread with latest-generation macro blocks and an adaptive Black Chilli compound (activated depending on how the tyre vibrates in different driving and braking conditions and longitudinal and lateral acceleration), with polymer chains responsible for a useful compromise between the highest reduction of rolling resistance and maximum braking on wet and dry; profile characteristics and the dynamic rigidity of the load area maximize the ground contact area. The rest is due to more even distribution of stress on the side and the differentiated rigidity of the area next to the bead, which is modulated by special compounds. To check the performance attributed to the ContiEcoContact 5 and try out the plate characteristics of the ContiSportContact 5, Continental organized a series of test drives on and off the Algarve international racetrack, a modern structure built four years ago on 300 hectares in the hills surrounding Portimão. Once on the track with a dozen different cars from the Audi TT RS to the BMW 135i MSport and the Mini Cooper S, from the Golf R to the Peugeot RCZ and Audi A7 Sportback, the Fiat 500 Abarth and the Volvo S60, the sporty qualities of the ContiSportContact 5 were obvious. Without exaggerating the characteristics of grip and stability when cornering, it demonstrated the driving and braking precision that were also found in the test on its big brother ContiSportContact 5P.
Consumption trials in the field
The result was a tyre capable of giving a comforting feeling of safety and control, even in the most critical conditions where its progressive behaviour is undoubtedly an added value. And the assessment did not change when going from the more peppery sports car to the luxury saloon. A short track next to the splendid main track hosted the test of the ContiEcoContact 5 on the wet in a straight comparison with its predecessor and the BluEco prototype for electric vehicles: a comparison of the three sets of tyres mounted on identical BMW 135s to be driven at speed on twists and turns and with braking in the shortest distance possible on very smooth asphalt with a film of water. Entrusted to telemeter data (and calculated as an average of the values recorded by a group of journalists-testers), the response, that had already emerged from subjective impressions, decreed the superiority of the new ContiEcoContact 5: marginal but in any case noticeable compared to the previous model, more obvious compared to the prototype, both for braking and grip (assessed on the basis of lateral acceleration), and very logical if we consider the BluEco’s vocation for low rolling resistance. Which was proved in the next text on consumption carried out in the same conditions (a gps indicated the gear to be used and checked that the speed always stayed within preset intervals) up and down a road outside the track: at the wheel of a small fleet of Volkswagen Golfs, the comparison of three with group telemeter indications, were in favour of the BluEco, which gave a saving in fuel consumption of about 0.5 litres per 100 km compared to the ContiEcoContact 5, which was more frugal than the ContiEcoContact 3 to the same extent.
• The eco-tyres of a plausible future
The reduction in obligatory stages of average CO2 emissions from 130 g/km for vehicles registered next year to 95 by 2020: this target set by the EU is closely bound to the reduction of tyre rolling resistance, which contributes to vehicle consumption (and therefore to the emission of greenhouse gas) by about 20%.
It is probable that tomorrow electric vehicles will have new types of tyres: a market segment for the 5% of electric vehicles estimated to be in circulation in Europe by 2020, which have narrower tyres with a wider diameter – a standard of 195/55 R20 compared to the conventional 205/55 R16 -, with the same load values but higher pressures.