Spent an interesting afternoon at the local Bira circuit with the friendly folk from Yokohama. They were presenting the latest tyre technology with their Yokohama Advan dB tyres.
Now dB stands for decibel, the unit of sound pressure levels, and the slogan for these latest tyres was “The Power of Silence”, so taking them to a racing circuit was certainly a brave move for Yokohama.
Wet braking test
The afternoon was split into four sections, with the first being a demonstration of rolling resistance, whereby a Lexus IS 250 on the new Yokohama Advan dB rolled further than it did when fitted with other tyres, all other factors being equal, such as tyre pressures. With less rolling resistance, the ordinary driver could expect to go further on a tank full, than otherwise.
The next section explored Noise Vibration Harmonics (NVH) and cornering grip. This time we had identical Toyota Camry’s, with one on the new tyre and the other on the old tyre. Quite frankly, when driving over rumble strips placed on the track, I found no difference between the two. Both went thump-thump-thump. However, there were a couple of slalom courses marked out with witches hats and the new tyre was certainly superior, requiring less steering input to whistle down the slaloms. That section definitely went to the new Advan dB.
I also went trackside to listen to the Camry’s being put through the slalom, and there was no squeal at all. You could hear the tyres gripping, but not protesting.
The third section was a direct comparison between two identical Camry’s braking on wet bitumen, with a part of the straight continuously watered. One car on the old rubber and the second car on the new. The wet braking area was entered at 80 kph and when at the marker, the brakes were fully applied. The Camry’s both had ABS, which worked well both times, but the car with the new compound braked consistently in 15 percent shorter distance. That could mean the difference between a close shave and an expensive insurance claim. This was the most impressive result for me, as it was easy to show the reduced braking distance.
Asymmetric tread pattern
The final part of the afternoon was a ‘leisurely’ trip from the Bira Circuit to the Silverlake Vineyard and return, escorted and led by the flashing lights and sirens of the Tourist Police. Now I know what it is like to drive in a royal cavalcade.
For me, this did not really demonstrate anything about the new tyres, but rather it showed what a quiet and comfortable vehicle is the new Camry. Unfortunately the two liter engine certainly does not make this model Camry a sports saloon. I’m afraid I would have to say the small engined Camry was rather dull.
But back to the tyres. The already quiet dB pattern tread has been improved by moving to an asymmetrical pattern especially for the Advan dB. With tread blocks very close to each other, this minimizes tread movement, which can be the reason for noisy tyres. It was also interesting to note there were no large side sipes to clear water, and the tyre also featured round shoulders, meaning the sidewalls could do some work, adding to good response to steering input. The longitudinal grooves were quite deep and designed the allow the tyre to slice through the water and not aquaplane. The braking results showed that this concept really did work. Design technology fostered during many years of developing high-performance Advan tyres has been fully utilized to provide the running safety, control and comfortable ride required for high-performance and prestige automobiles. Advan are the tyres used in the World Touring Car championships, for example.
I know that tyre performance can often be very subjective, but there were a couple of very objective tests which showed a superiority of the new Yokohama Advan dB. You will go further on a tank full and under brakes will pull up earlier, hopefully avoiding a nose to tail.
My thanks go to Yokohama’s managing director, Yasushi Iida for the opportunity to evaluate his latest tyre, which, by the way, is a Japanese import, the local Yokohama works in Rayong being for light truck tyres only.