Yokohama Rubber recently offered the regional media an opportunity to test drive its new dbV552, the latest addition to its flagship global Advan tyre brand. Invited by YHI Malaysia, the sole distributor of Yokohama tyres in Malaysia, The Tyreman was honoured to be among the media from Singapore, Hong Kong, Vietnam, Cambodia, Myanmar and Thailand to test drive this product that is targeted at the Asian market.
The event took place at the Yokohama Tire Test Center of Asia (TTCA) in Rayong Province, Thailand, which is the company’s second comprehensive tyre proving ground after that in Japan.
“Yokohama Advan dB V552 is a premium comfort tyre targeted at luxury sedans. It creates breath-taking silence and brings you a sense of tension beyond comfort. Silence is greatly enhanced through meticulous redesign that includes a review of all design elements such as pattern design, profile shape, internal structure, type of parts, size of parts and surface contact configuration. It is not only Yokohama’s most silent tyre ever, but also demonstrates improvement in wet performance and fuel efficiency with the application of a newly developed dB compound,” said Kohei Obata of The Yokohama Rubber Co, Ltd Consumer Tire Product Planning Department.
Also present were Yokohama Asia Co, Ltd President Toru Suzuki, Marketing Manager Sayuri Kobata and YHI (Malaysia) Sdn Bhd Sales Manager- Commercial Edward Ho.
Noise causes an unpleasant hearing sensation or even discomfort to the driver and passenger. All tyres generate noise while rolling on the road surface and the noise is produced mainly from the tyre pattern or road. Yokohama has put its effort in reducing the tyre noise through detailed pattern design, subdivided into 144, to suppress the concurrence of noise. Chamfering applied everywhere optimises block rigidity and suppresses uneven wear so that the quietness of the brand new tyre would last for a long time. The grooves, which look like one connection, are actually moved in millimetres. By shifting the timing of the grounding, the generated noise is dispersed. It is said this precise groove arrangement prevents the motorist from concentrating on a specific frequency band and reduced hash noise. Its steering stability and silent performance is greatly improved, thanks to the staggered arrangement of grooves and sipes.
The redesigned silent tyre structure and rubber compound of dB V552 also contributed to its silent performance. Examples include the use of silent based compound that improves quietness by suppressing vibration, fuel-efficient side compound that enhances fuel efficiency on the sidewall and the adoption of a wider belt than that of a general tyre. The belt-edge cover, which enhances the rigidity at the end of the belt, controls vibration on the shoulder part. There is also the side-reinforcement belt for firm handling and ride comfort for heavy-weight premium cars.
Compared to the previous generation dB V551, the new dB V552 is said to have 30 per cent reduced road noise level and 20 per cent reduced pattern noise. It also show improvements in other parameters, such as 8 per cent better wet stability, 6 per cent better wet grip, 5 per cent better rolling resistance (fuel save), 3 per cent better anti-hydro and 1 per cent better wet circle performance.
After the brief product introduction, we went behind the wheel to put the dB V552 to a series of tests. There were four test stations; noise station, wet braking and handling station, wet circle and south handling.
Our first area was the noise station, where we were driven on a specific course in two Camrys, one equipped with dB V551 and the other with new dB V552. We were asked to listen attentively to the noise level of the two tyres running on the rough road surface and a fine road surface. We found the Advan dB V552 quieter compared to the dB V551.
The second station required us to experience wet braking by driving up to 80km/h and performing an emergency stop, followed by a slalom run on a wet surface with the new tyres. As a passenger, we found that the wet braking was good and the road-holding and grip gave us total confidence.
Subsequently, we moved to the third station that consisted of a wet circle and south handling. The wet circle test was basically to test tyre adhesion and grip on the wet surface. We were asked to make a comparison between the dB V551 and dB V 552 in a circular driving manner. The new dB V552 demonstrated better grip and adhesion and we managed to clock 55km/h compared to 50km/h with dB V551.
Meanwhile, the south handling test was to experience the dry performance of the dB V552. For this test, we drove a Mercedes-Benz C-Class C350e hybrid through a narrow and winding path, and up and down a slope with the recommended speed of 60km/h. The new tyres provided good road-holding, control and grip in the dry.
According to Obata, the new Advan dB V552 is produced in Japan. Suitable for daily driving with increased silence, safety and confidence, the tyre has 45 sizes ranging from 14 to 20 inches wide and 155 to 265mm wide.
This 1.69-million square metre site of TTCA was initially equipped with a 4.1km high speed track with a 1-kilometre straightway enabling high-speed running tests of above 200km/h, a multipurpose track covering approximately 100,000 square metres, a 4.2-kilometre course that encircles the high-speed course to represent general road conditions in Asia, and a rough road course for testing tyre durability. The 1km multipurpose track enables testing tyre performance during high-speed lane changes while driving through a slalom course. It is also equipped with a wet-test course and a special course that enables evaluation of ride comfort and noise generation.
The expansion exercise in 2013 added 4 new test courses – a 2.5-kilometre dry-test course and a 1.5-kilometre wet-test course for handling tests, a skid pad and a corner hydroplaning test section. The two handling test courses enable the testing of overall tyre performance and compatibility with specific vehicles under dry and wet road conditions, while the skid pad is used for testing tyre grip performance on wet roads.
