Technology for greater active safety: BMW Group opts for Runflat tires

Munich. With the launch of the self-supporting tire featuring emergency running
characteristics, the BMW Group is once again playing a pioneering role by
increasing active safety on the road yet again.

All BMW Z4, 1 and 6 Series models as well as the MINI Cooper S and the new 3
Series sedan are already being fitted with Runflat tires as standard. The great
benefit of these tires is that in the event of a puncture, and the complete
loss of air pressure within the tire, it is possible to continue the journey at
speeds of up to 80 km/h, without the immediate need for a wheel replacement.
The tires are also available as optional extras for the BMW 5 and 7 Series and
the MINI and MINI Cooper.

One of Germany's leading automobile magazines has conducted extensive driving
tests, which have served to confirm the benefits of the Runflat tires now being
employed by BMW. Compared with all other tire systems, Runflat tires offer
increased dynamics under normal conditions, better handling, and shorter
braking distances in the event of a breakdown, not to mention the increased
comfort compared to other emergency running concepts.

No more fear of punctures thanks to the special tire construction

It is the nightmare of every car driver to suddenly have to suffer puncture in
a long motorway tunnel or perhaps at night during a rainstorm with no hard
shoulder available.But now there is the self-supporting emergency tire with the
emergency running characteristics, known as the Runflat tire. With these tires
fitted to your car, it is no longer necessary to stop immediately to change the
wheel. You can continue driving in comfort until you reach the next garage.

The tire employs additional elastic inlays made from an extremely
heat-resistant rubber mixture, in the side walls. This prevents the tire
becoming so hot that it bursts into flames. This is why the self-supporting
tire is able to continue going for distances of up to 150 km, with the vehicle
fully loaded, despite having lost all of its internal air pressure. With
lighter loads or if a residual pressure remains in the tire, this distance is
several times higher.

Drive on in confidence, even with a burst tire

But that is not all. The new tire technology also offers extremely high safety,
in particular in the event of a sudden loss in tire pressure. The specially
formed EH2 wheel rims mean that the Runflat tire does not lose contact with the
wheel if air escapes suddenly, which represents a substantial increase in
safety when driving at high speeds along bendy roads.

When a conventional tire bursts, the driver is in most cases confronted with a
problem with no solution. In contrast, a car fitted with Runflat tires remains
easy to control and retains stability within its lane, even in an extreme
situation such as this. Extreme steering manoeuvres are unnecessary, not least
because the ABS, ASC and DSC systems all remain functional and continue to
support the driver in controlling his vehicle.

A further advantage of this special type of wheel compared with competing
systems is that it is always possible to fit a standard tire as a spare, in the
event that the corresponding type of Runflat tire is not available in the short
term.

Increased safety from automatic tire pressure control

The significant increase in safety which these tires afford the driver is not
at the cost of comfort on the road, and it even leads to improved dynamics.
Since the running characteristics and the visual appearance of the Runflat
tires remain inconspicuous, even after pressure loss, it is possible that the
driver does not even notice that he has suffered a puncture. Which is why
whenever these tires are fitted, it is always in combination with a standard
Tire Puncture Indicator.

The Tire Puncture Indicator gives both visual and audible warning in the event
of pressure loss. Most tire damage is preceded by a gradual drop in pressure.
This system calculates the tire pressures from their respective rotational
speeds, as registered by the ABS sensors.

Less weight and more luggage space in the rear

It isn't just the increased safety from which the customer is set to benefit.
Since it is no longer necessary to carry a spare wheel or a jack, the vehicle
weight falls by up to 27 kilograms in the case of the 7 Series models. Not only
that, but it also frees up an additional 90 litres of luggage space in the
luggage compartment. In the case of the 3 Series, the weight saving is 10
kilograms and additional luggage compartment space of the order of 70 liters.

Already in broad use

With its broad-based launch of this new safety system, the BMW Group has once
more demonstrated its pioneering role and leading position within the market.
This tire system has been available since 2000in the BMW Z8, where it was
fitted as standard. The high-safety tires are now being gradually introduced in
all the remaining BMW and MINI model series.

The 1 and 3 Series sedan models, the 6 Series, Z4, Z8 and MINI Cooper S are all
supplied with the new tires fitted as standard. In the case of the 5 and 7
Series, MINI and MINI Cooper Runflat tires are available in combination with
attractive, light-metal wheels, upon request. Approximately 65 percent of all
BMW 5 Series and MINI models are currently being ordered with the optional
Runflat tires. The M vehicle series is equipped with the M Mobility System.