Dunlop launches latest race-inspired rubber – full report

At the end of February Dunlop announced the launch of its Sport Maxx Race and Sport Maxx RT products at Spain’s Ascari Race track. Designed to help some of the world’s fastest cars perform, Dunlop says the Race iteration will be fitted to key models such as the Mercedes SLS and C63 AMG Black Series, Audi’s TT RS and R8, the Porsche 911 GT3 and the BMW M5. The RT is aimed at original equipment manufacturers that are introducing 17 and 18-inch rims ahead of 16 inches; the Sport Maxx RT is the brand’s attempt to capitalise on the market expansion in these sizes on leading performance brands such as Audi, Maserati, Mini, BMW, Jaguar, and Mercedes AMG.

But why develop a new sports car-orientated tyre? We might hear talk of bail-outs and euro-crisis ad nauseam on the news, but taking a longer view, this tyre segment is growing in line with sector growth in the high performance car parc of an estimated 7 per cent. And with Dunlop’s continued support of supply to high level touring car and GT-class motorsport series (such as the British Touring Car Championship), there is a constant stream of competition quality tyre data with which the company can develop its products. Nowhere in the company’s range is this more clearly seen that in the creation of the new Dunlop Sport Maxx Race and Sport Maxx RT tyres.

Dunlop Sport Maxx Race

Fundamentally the Sport Maxx Race is a road legal track day tyre. Dunlop is keen to point out its ultra-high performance pedigree and associations with some of the latest vehicle technology such as Mercedes’ C63, but the UHP intentions of the tyre are immediately obvious when you look at it.

The first thing that you notice is what Dunlop calls its “super massive shoulder.” It may be par for the course for an asymmetrically designed UHP tyre to feature a large shoulder, but the sheer size of the Sport Maxx Race’s is quite striking. According to the company, this particular design feature helps to ensure that drivers keep their vehicles well-balanced in corners, offering higher cornering grip on the track (around 11 per cent better than the benchmark tyre, says Dunlop). Apparent further improvements in cornering grip are delivered thanks to high angle ribs, ensuring increased lateral stiffness. Further high speed stability is said to be driven by a hybrid overlay featuring Aramid. And the tyre further provides drivers with a strong confidence on wet road surfaces, thanks to four inner circumferential grooves for better water drainage, resulting in 2.3 metre shorter wet stopping distances.

Other performance enhancements come from the distinctly less visible high-performance compound employed in the production of the Sport Maxx Race. According to the company, the tyre features a blend of what Dunlop calls a “race-proven polymer and a traction enhancing plastifier,” leading to higher compound micro adaptability to road surface. The visco-elastic properties of the tyre’s compound may be is itself derived from motorsport, but what does this mean for tyre life? If time-trial abuse Top Gear recently put a Mercedes C63 through is anything to go by (and, due to the fact that Jeremy Clarkson didn’t reveal which tyre brand he was destroying, this is by no means clear) this could be one area that has be de-prioritised in favour of sheer dry performance, greatly improved wet handling and even better rolling resistance. But if this is the case, it would not be unusual in a tyre aimed at this specialist sector.

Improved fuel economy

Improved rolling resistance in a supercar tyre? Strange as it may seem, in addition to the power and handling enhancement built into the Sport Maxx Race by Dunlop engineers, the new tyre also offers superior fuel economy. According to the company’s tyre developers, this improvement is an example of a pleasant happenstance coming – as they do – more by luck than judgement. Dunlop reports that the new tyre offers “superior fuel economy” as a result of improvements in construction that meant the overall tyre ended up weighing less than the team might first have expected. (This specific improvement probably relates to the use of lightweight, but very strong aramid in the casing). The irony is that despite having produced a lighter, more fuel efficient tyre this literally wasn’t on the agenda and was not said to have been something that the developers were intentionally aiming for. That said, this fact has the potential to pay dividends with consumers conscious of how much their pet powerhouses are already costing them in fuel and is also likely to paint a rosy picture of the product when the tyre labelling legislation kicks in later this year.

Dunlop reports that it will initially release the tyre in 28 stock-keeping units, covering 85 per cent of 16 – 18-inch UHP sizes. The Mercedes C63 AMG Black and the Audi TT RS are reportedly specified OE fitments already.

Sport Maxx RT replaces SP Sportmaxx TT

As we have seen the new Sport Maxx RT (Racing Technology) road tyre is designed  for the driving enthusiast. However, according Dunlop, the tyre that is set to replace the SP Sportmaxx TT will “deliver to the needs of the continent’s most passionate driving aficionados, who savour the feeling of being in control of significant horsepower and dream of being in pole position at some of the world’s most prestigious races.”

According to the company it combines the best of over 120 years of experience on the track and on the road and “is a tyre with heritage and power… just bursting to get out.”

The new tyre has been developed to deliver performance to the road, with racing technology know-how integrated into the tyre’s design and development. On road surfaces the Sport Maxx RT is designed to deliver enhanced grip thanks to its own variation of the motorsport derived compound of its even sportier cousin, which provides increased adaptability to both dry and wet road surfaces. The tyre also aims to deliver high handling stability, built on its own large outer shoulder block, increasing the contact area when cornering, especially at high speeds.

However, a performance emphasis doesn’t mean it is a fairweather tyre. In wet the Sport Maxx RT aims to deliver the necessary performance to the road, building on its racing heritage. According to the company, the tyre features solid aquaplaning performances built on a set of large central grooves which increase water flow volumes. A round footprint allows water to be pushed out via the lateral grooves so the tyre delivers its performance to the road, and not the water surface.

A shorter braking distance, especially at high speed is delivered by short-braking blocks, set into the tread pattern of the tyre. These blocks, reinforced by lateral blocks reportedly offer an anti-lift effect on the trailing edge thanks to their increased stiffness. Supporting the need for reduced fuel consumption are the material distribution, which reduces heat generation, and an aerodynamic sidewall, which reduces air drag.

In order to demonstrate the performance of its recent debutant, Dunlop points to TÜV tests run with the new Sport Maxx RT. According to the company, these show that compared to its closest competitors, the Sport Maxx RT outclasses in both dry and wet braking results by showing a significant 7 per cent lead. Additionally, the independent tests point to a clear 11 per cent better rolling resistance, compared to its key competitors on the market .

The Sport Maxx RT introduction comes at a time when drivers and original equipment manufacturers are increasingly walking away from 16 inch rims and expanding strongly into 17 and 18 inch rims, two sizes which the Sport Maxx RT will cater to. As such, the range focuses on these sizes. The new tyre is developed to fit the needs of some of the road’s leading performance brands including the Audi, Maserati, Mini, BMW, Jaguar, and the Mercedes AMG, to mention but a few.