Bridgestone Tire S-04 Pole Position - Tire Test - Eurotuner Magazine

Although it recently stepped back from its Formula 1 supply contract, Bridgestone is indelibly linked to performance tires through its Potenza range. Launched in the early ’80s, its RE91 tire led to a development program with Porsche, which saw the RE71 approved by the German carmaker and even specified for the infamous 959 model. This was followed by fitments for the Ferrari Testarossa, 348 and even the awesome Enzo.

Since then, it’s reputation for building high-performance tires has grown, along with a general competence in all areas. To prove the point, the company introduced its new Potenza S-04 Pole Position summer performance tire, RE970AS all-season and RE960AS RFT run-flat tires. All are from the Potenza Pole Position family, indicating ultra-high performance applications.

We had a chance to drive them all, back-to-back and against competitors to gauge their overall merit. We came away impressed with the S-04 and RFT in particular, so we’ll concentrate on these.

The new S-04 PP replaces the older RE050A for wet and dry summer use, having an asymmetric tread pattern with dry-grip outer tread blocks and wet-weather inner grooves. What’s more, they tapered the tread blocks to increase stability, even adding a RENOA “silencer” groove to trap road noise and make them run quieter.

With 45 sizes in the Y speed rating and a wear rating of 280 AA A, they should last reasonably well and we definitely found they had the grip we were looking for in the Audi S4 and BMW Z4 cars we sampled them on. The levels of grip are high and they seemed predictable in the corners at higher speeds.

Run-Flats
While the RE970AS all-season tire impressed with its wet grip and good behavior at higher speeds in the dry, it was the Potenza RE960AS Pole Position RFT run-flat tire that got our attention.

The 970 has replaced the 960 for all-season duties, but the 960 remains in a new run-flat form that could be a godsend to drivers on run-flat tires.

Anybody buying a new BMW in particular knows you get run-flat tires and no spare. The idea is to save the weight of a spare and give you “get home” capability in an emergency. The problem has been that replacement run-flat tires are incredibly expensive, the ride comfort is somewhat questionable and they often don’t last long.

As a supplier of OE run-flat tires to BMW, Bridgestone (among others) has come under criticism for the quality of these tires. So the new RE960AS RFT is a third generation run-flat aimed at quelling some of the criticism and offering an alternative to the replacement tires sold by BMW dealers.

The 3G RFT technology combines curious Cooling Fins on the reinforced sidewalls. The fins are intended to control heat build up when a tire is running flat.

The upside of this technology is an overall reduction in the weight of the tire and its sidewall stiffness (which previously had to be super-stiff to withstand extended running while underinflated). The result is improved ride comfort, lower rolling resistance and improved wear versus its previous run-flat tires.

We tested the RE960AS RFT against non-run-flat tires and when underinflated. In all honesty, it was difficult to detect much difference between the new RFT and a conventional all-season tire in terms of comfort and grip. What’s more, they still drove well when underinflated in a second test.

There are nine popular OE run-flat sizes available at present and it has a 400 AA A wear rating for longer life.

So if you’re looking for replacement run-flats, the RE960AS RFT is worth investigating and, like all three tires here, they come with a 30-day buy-and-try guarantee as well as Bridgestone’s Platinum Pact three-year replacement limited warranty. The run-flats even have a 40,000-mile limited treadwear warranty for extra piece of mind.