Established since 1976
Established since 1976
By Lee Pang Seng
CHANGE is a constant and it applies to everything, not least of all the automotive and its ancillary industries. Tyres are a must and vehicle development is often done with the tyres the car manufacturers would like to use. The vehicle’s suspension system is normally geared towards the range of tyres it is running on.
That specialisation is more critical in sports oriented models while the performance demands for the general range are wider. It nevertheless gives an insight into the complementary nature of the vehicle dynamic performance between its suspension design and its four contacts with the road; the tyres.
The swing in demand towards SUVs (sport utility vehicles) was significant over the last five years in both mature and growing markets and this had not been overlooked by the tyre manufacturers. The increase in demand applies across the vehicle model range, from entry level models to premium SUVs. In the Asia-Pacific region, the luxury SUV segment is expected to grow at a compound annual growth rate of 2-5 per cent from 2012 to 2022.
Goodyear acknowledges this trend by expanding on its award-winning EfficientGrip tyre range with the Performance SUV highway series. This is targeted at premium SUVs for which the numbers had grown just as fast as the lower range models. Obviously, those driving such SUVs would like a tyre to complement its upmarket character.
The two main features that went into the design of the EfficientGrip Performance SUV tyre are Goodyear’s QuietTred and FlexContact technologies. This is supported by even higher levels of wet grip performance, which is all too relevant in the Asia Pacific region where seasonal rain and wet roads are another constant.
QuietTred Technology
Goodyear increased the number of pitches and optimised the distribution on the tread pattern. This is seen in the reduced or smaller block sizes that are found to lower the impact with the road, leading to lower radiated noise.
For the tyre shoulders on both sides, the pattern shows a closed groove design. The benefit reaped is in the low radiated noise generated through the reduced radial air pumping as the tyre rotates. That is enjoyed by the vehicle occupants in a quiet ride as a result of the reduced exterior and interior noise levels.
For the central rib area where road grip is paramount, Goodyear has gone for an optimised cavity shape and non-skid distribution properties. This is said to have led to an optimised footprint shape and pressure distribution. With that, the gains come in less vibrations generated and regular wear throughout the tyre life span.
FlexContact Technology
This approach looks deeper into the tyre or the under layers that form the tyre carcass. The first is what Goodyear calls the Shock Absorbing Cushion Layer Compound with optimised formulation. It is an under tread base compound with reduced hysteresis to help avoid road-induced tread block movements and reduce tyre vibration.
This is supported by another layer of heavy gauge under tread and barrier gum strip. Goodyear says this increases the insulation of the tyre structure on the road for better damping and lesser vibration so that vehicle occupants could enjoy a more comfortable ride.
The third area is the use of a hexagonal bead for the section of the tyre that grips the wheel. This innovative bead shape is found during product trials and evaluation to enhance rim contact and reduce vibration.
Better Wet Performance
Goodyear says ‘excellent’ wet performance is achieved through a high performance cap compound with leading edge technology. This basically means the use of new innovative polymers in the tread section with optimised microstructures for increased grip in wet road conditions. It is also said to increase molecular bonding in the tyre tread for ‘precise’ steering response.
Helping in the efficient water dispersion to achieve optimum contact patch with the wet road surface are the wider and reinforced shoulder blocks. This is said to increase the road contact area, especially during braking when you need maximum road grip to come to a safe stop.
There are also the wider centreline sipes to assist in the optimum dispersal of water. Goodyear says this design balances the contact area and water evacuation route to improve wet braking and curved aquaplaning (aquaplaning while driving through corners).
An additional feature is a beefier sidewall with the use of more material to protect the rim/wheel and tyre against road kerbs. This tyre is available in Malaysia for rim sizes of 17-inch to 20-inch and there are 20 sizes to cater a broad segment of the market.
EfficientGrip Performance SUV in Buriram
Following the regional launch of the EfficientGrip Performance SUV range in Buriram, Thailand, Goodyear arranged for the media to get a firsthand feel of the tyre qualities through a few drive routines and demonstrations at the racing circuit. By the way, this newly built circuit would host its first MotoGP event in 2018.
Being a tyre for premium SUVs, the vehicles used clearly reflected the status quo being a selection of Mercedes-Benz and BMW vehicles. And of course there had to be a respectable rival brand to measure up against in performance and for comparison in dynamic feel and handling performance. It wasn’t as many as the ones used during the product presentation following the launch for the sake of convenience and simple A-B notes.
It began with a demonstration of the quieter and better braking performance of the EfficientGrip Performance SUV against the rival tyre. A Mercedes-Benz GLC was used and it ran on the Goodyear tyres first before they were changed to the rival brand there and then. Using a single car and driver allowed a consistent measure of the respective tyre’s performance.
The sound test was done at a set speed on both tyres while the braking performance was done on dry and wet surfaces (the latter was done by spraying water on the track surface). As expected, the EfficientGrip Performance SUV came out tops; its noise level was measured at 74.1dB while the rival brand generated more noise at 76.3. In braking performance, the Goodyears brought the GLC to a stop over a shorter distance by a metre in difference.
Handling performance
We got to grips with the EfficientGrip Performance SUV in three of the four routines arranged. The road drive around Buriram was given a miss as none of the Malaysian media contingent brought an international driving licence. As most of us had driven in Thailand before without being asked for one, we were caught out on this one. Apparently, it had to do with the insurance coverage.
The first routine was to feel the dynamic quality of the tyre through its improved steering response. There was no comparison to be made here and it was purely to enjoy the ‘high speed handling’ characteristics by driving a BMW X1 through a quick lane change course at 80km/h and a sharp corner at 50-60km/h. Both were confidently executed without any drama or wheel scrubbing, and vehicle poise and balance was easily maintained.
Routine two was a bit more fun as it involved driving a BMW X3 SUV through a wet slalom course followed by a dry slalom section about 500 metres down the track. Again, this was done solely on the EfficientGrip Performance SUV tyres to experience the wet and dry steering precision provided by the tyre when navigating such courses.
The only problem was the entry speed into the first slalom course, a wet one, was not properly communicated during the pre-drive briefing. As the media group was rather big and we were standing at the back didn’t help. Needless to say we went into the course a bit faster than suggested and well, even the best of tyres couldn’t do the impossible. A few cones got knocked over but we sobered down for the dry slalom course and enjoyed the good grip provided in quick directional changes.
The final routine we took part in was to gauge the tyre’s good wet lateral grip. This was done against a rival brand to highlight the difference in performance. We were to drive two Mercedes-Benz GLCs with each shod with the respective tyres in succession to gain that experience.
It was simple routine but good enough to highlight the difference. We were to enter a sweeping curve of the race circuit, which was artificially wet, by lifting our foot off the accelerator at 60km/h. There was no possibility of us going any faster into the corner as the cruising speed was set at 60km/h.
The Mercedes-Benz GLC running on the EfficientGrip Performance SUV tyres took the designated line through the wet sweeping curve without deviating from it. Nor was there any inclination of the vehicle to want to stray from the route.
It was different with the other Mercedes GLC running on the rival brand. We could feel mild understeer coming in mid-way through the corner, leading to the SUV drifting wide as we exited the curve. The corner speed might be slow but the difference in wet lateral grip between the two tyres was very clear, in favour of Goodyear.
