Exploring Potenza Sportís Potential at Sepang

By Lee Pang Seng

THE Bridgestone Potenza Sport is a flagship tyre launched in August 2021 to replace the Potenza S007A. Yes, you read that right; this tyre was launched two years ago. Thanks to the Covid-19 pandemic, Bridgestone Tyres Sales (Malaysia) Sdn Bhd decided to keep a low profile on the tyre till now.

The momentum to spread awareness on this latest Bridgestone flagship tyre probably came about with the Lamborghini Huracan STO launch in mid-2022. Even so, Bridgestone Malaysia decided to take its time before organising a media impression of the Potenza Sport at the Sepang International Circuit.

This Sepang event also took a different perspective from previous Bridgestone tyre impression arrangements in that the media only had to focus on the Potenza Sport itself. There were no comparison trials against the S007A or rival equivalents (such as the Michelin Pilot Sport 4 S, Goodyear Eagle F1 Sport or Continental Sport Contact 7). Instead, there were three sessions to showcase the tyre’s braking performance, good steering response and dynamic handling limits to gain an idea what the Potenza Sport was all about.

The Potenza Sport boasts a sporty carcass package that includes the textiles used, side shape and gauges, rim guard and bead filler. Bridgestone says it is all tailored to balance a sporty feeling and rolling resistance. The benefits come in maximising dry handling performance and ‘lightning-quick’ steering response and optimising rolling resistance.

Next comes the tread area that features an optimised distribution of ribs and voids to maximise the evacuation of water when running on wet roads, improve cornering power to provide more dynamic driving and maximising the braking potential to stop the car over a shorter distance.

Here, there is also a rib variable profile for the tread pattern that Bridgestone says would provide a more efficient contact pressure with the road surface and higher wet friction that would be beneficial on wet road surfaces.

Playing its part too are the innovative 3D sipes, which look like little cuts on the tread area, to increase shear stiffness and provide benefits in better braking performance and wear abrasion resistance. Bridgestone says the tyre with the standard 1D sipes has a braking potential of 100 per cent while the tyre with the 3D sipes improves that to 102 per cent.

Lastly, the Potenza Sport has an asymmetric wall angle that is said to increase lateral stiffness. This in turn reduces tread block deformation and excessive movements during cornering for a better performance.

The tread compounds are said to be formulated with an innovative mixing technology to enhance tyre stiffness for greater stability on wet and dry road surfaces. There is also the combination of high-performance steel reinforcement and a new hybrid crown reinforcement to deliver ‘superb’ handling and stability at high speeds.

Bridgestone says that during the tyre design and development stage, virtual tyre development played a critical role in allowing the tyre maker to accurately predict the tyre’s performance without having to physically produce and test it. This is said to be more environmentally friendly due to the reduced resources required as well as shortening the development process and accelerating time to market.

Bridgestone did a performance comparison of the Potenza Sport against the predecessor Potenza S007A (both sizes were 235/35 ZR19 fitted to a Subaru Impreza STI 2012 model) at its Thailand Proving Ground near Bangkok. The results revealed improvements all round except for the noise generated by the respective tyre, which was of the same level.

The Potenza Sport’s biggest improvements were in wet cornering grip that was up 14 per cent, followed by ride comfort (10 per cent), wet braking (seven per cent), wet handling, dry handling and high-speed stability (all up five per cent each) and dry braking (two per cent). The high-speed stability runs covered cornering speeds at 130km/h and straight-line speeds of 160-180km/h.

Bridgestone Malaysia has made available 44 sizes of the Potenza Sport, ranging from 225/40 R18 to 325/35 R22. And flagship tyres don’t come cheap with these Bridgestones starting from above RM900 to above RM2000.

Sepang Potenza Sport Impression

It just so happened that it rained very heavily on the morning of the Bridgestone event and track conditions were somewhat compromised for the respective routines we were involved in. Thankfully the sun was out in its blazing glory when we were about to begin the first routine; even so, the track surface was kind of ‘iffy’. You could say in Formula One parlance that when we started with the wet braking session, the track was good for F1 intermediate tyres.

This was done in a Mercedes-Benz C300 that ran on 225/40 R19 Bridgestone Potenza Sport tyres. The routine was to accelerate to a point where we would hit the brakes hard; on both runs, the C300 stopped more or less at the same point although at different speed of 75km/h for the first run and 80km/h for the second (when we selected Sport mode). We used the track cones placed in the braking section as our guide.

By the time we started the dry braking routine, the track surface was dry enough (good for F1 cars to switch to dry tyres). Here, we did the runs in a BMW 530i shod with the same size Potenza Sport tyres. The two runs also returned consistent stopping distances, with the 530i stopping about one and a half cones shorter than that for the wet braking distance.

Our second routine was the slalom run that included turning back and coming to a complete stop within a designated area. The car used was a Volkswagen Golf GTi that ran on 225/40 R18 Potenza Sport tyres. This session was to allow us to experience the tyre’s quick steering response and was a timed trial. We weren’t the fastest among the media people in our group but we felt pretty confident driving the Golf GTi quickly through the slalom course with the good steering response.

The final routine was a two-lap drive along the South Track of the SIC in a BMW 330i; the tyres fitted to the car were 265/35 R18 Potenza Sport tyres. Following a lead car, the intention was to allow us to feel the tyre’s performance through the corners at good speeds. Cones were placed along the circuit to guide us on the braking points and optimal cornering lines.
The first lap was well and good and the Potenza Sport showed its good grip potential through the respective corners at good speeds. We decided to push it a bit more during the second lap by choosing not to hit the brakes for one of the corners as we felt the speed was a bit too low. That was to be our undoing.

We realised that we were entering the corner at too high a speed and although we eased off the accelerator pedal, we drifted wide onto the grass shoulder. And wet grass is a driver’s hell as it offers absolutely no grip. As much as we tried to stabilise the car, we eventually came to a stop on the opposite side of the track, thanks in part to the BMW’s active safety system.
 
As it were, the Potenza Sport gave us the confidence to drive the 330i at good speeds around the circuit. It appeared to complement the car’s dynamic handling system, which lulled us into a false sense of confidence to push the limits further. And we found the limits and beyond, without incurring car damage other than our ego!