Bridgestone’s Innovative ‘Large and Narrow’ EP500 Tyre Fits on BMW i3


BMW’s newest i3, with its Li-ion battery offering an 80 to 100 mile range, is ideally suitable for urban driving, says BMW’s UK division. The car maker says that every feature and every little detail of their new electric car has been devised specially for city life.

Bridgestone states that the EP500 tyres are specially designed for fitment on the said vehicle and required adoption of a completely new concept. The tyre maker’s answer to BMW’s stringent requirements was what it calls the ‘ologic technology’.

The Ecopia EP500 ologic was launched in November 2013, with BMW i3. It comes in four size choices including 155/70 R19 84Q and 175/55 R20 85Q, and in two variants for winter. The Blizzak NV ologic winter variant is built from Bridgestone’s Multicell compound that rapidly clears water between the snowy surface and tyre. It hence improves road contact and grip.

The “Large and Narrow” Tyre

Bridgestone demonstrated that this technology exploits the synergies resulting from a large diameter in conjunction with narrow tyre width and tread pattern. It used the concept tyre – “Large & Narrow” – to show the same at the Geneva Motor Show in 2013.

The tyre giant says that such tyre dimensions tremendously improve aerodynamics and reduce rolling resistance, and offer an outstanding grip in the wet. Bridgestone bases these claims on the basis of comparative test results carried out in 2011, at its proving ground at Tochigi in Japan.

Can a tall and slender tyre be actually good at both, aerodynamics and on wet surfaces? Bridgestone explains that typically, the tread on tyres with smaller diameters, is prone to “deformation” due to excessive movement during driving. On the other hand, a tyre with larger diameter and greater belt tension remarkably reduces tyre deformation. It, in turn, conserves energy, which is otherwise lost via internal friction. This phenomenon helps in reducing rolling resistance.

In the same way, the concept of narrow tread enhances aerodynamics as well. However, the most impressive feat of ologic technology, in Bridgestone’s opinion, is that these drastic improvements do not result in compromised safety. EP500’s long contact patch, as compared to its slender width, plus the choice of tread compound and pattern, enhance grip under both dry and wet conditions.

Bridgestone Expresses Confidence

The CEO and president, Bridgestone Europe, Franco Annunziato, expressed that BMW i3 is absolutely a car for tomorrow. And that it has been an enormously challenging and a rewarding experience for Bridgestone to create an exclusive tyre for this exclusive vehicle.

He added that while Bridgestone considers energy efficiency a significant design criterion for all its tyres, the factor turns even more critical when it comes to an electric car. Bridgestone hence invested its entire expertise, skill and passion in building this innovative tyre concept. He further added that they are confident about EP500’s premium performance, high safety and economy, satisfying the consumers who expect ace products from both the brands.

Source: Tyre Blog
Published: 23 Jan 2014