Dry braking
Dry handling
Rolling resistance
Exterior noise
Rolling circumference
Tire wear
High speed capability
Snow handling
Wet handling
be reworked.’ The tests are carried out on every tyre
dimension, each of which has its own specification docu‑
ment with certain requirements.
During the European summer, winter tyres are tested in
New Zealand; the summer tyres are generally tested in
Europe. Porsche conducts the wet handling tests on
test tracks belonging to manufacturers in the tyre in-
dustry. The logistical work involved is immense: several
lorry loads of 200 or more tyres and five or six test
vehicles have to be planned and moved around. ‘We
don’t just test on racetracks, however. It goes without
saying that our cars also have to be tested on A roads
and motorways. This is done in the context of so-called
endurance tests.’ If all the criteria have been met after
the tests, Porsche grants its approval to the tyre manu-
facturer. The tyre is then given an N label, the Porsche
seal of approval for tyres. ‘Once the tyre goes into series
production, new problems can suddenly arise for the
manufacturer, because it is one thing producing 20 proto-
types, but quite another manufacturing 2,000 tyres,’
says Haupt, briefly outlining the problems associated
with series production.
Performance versus comfort
The extended model range has changed Porsche’s ap-
proach to tyre development: ‘We come from a pure
sports car segment,’ explains Haupt. ‘Accordingly, our
aim was always to be the best in class when it came to
performance, braking in dry conditions and lap times. It
is important to us that we hold the record for the fastest
lap time on the Northern Loop of the Nürburgring. This
is currently six minutes and 57 seconds in the 918 Spyder.
In other words, we also have to be extremely perform-
ance-oriented when developing tyres. However, as a
result of models like the Cayenne, the Panamera and
soon also the Macan, we are faced with the challenge of
improving the balance between comfort and perform-
ance. That goes for many components on the car and
also for the tyres.’
A shift in the markets has also contributed to the com-
plexity of Haupt’s remit: in China, for instance, Porsche
customers tend to drive their vehicles more frequently in
urban regions where there is often stop-and-go traffic.
‘We have to pay greater attention to comfort and exterior
noise here.’ Other challenges are issues such as redu-
cing CO
emissions and improving rolling resistance,
areas on which Porsche has worked hard in recent
years with the tyre industry. ‘In terms of tyre develop-
ment, on the one hand, we must achieve the best lap
times and good braking distances, aspects which call
for a compound that provides excellent grip. This is as-
sociated with a high degree of hysteresis, however,
which is manifested in poorer rolling resistance. On the
other hand, we have to develop tyres whose compound
reduces rolling resistance and thus CO
In this regard, Haupt and his team are constantly calling
for the tyre manufacturers to use new technologies and
materials, because the tyre has a very big influence on
reducing CO
emissions. ‘There will be a continued focus
on cutting CO
emissions in future, because such aspects
are crucial in terms of the social acceptance of our
vehicles,’ says Haupt.
It’s all about the compound
Since the tread compound is responsible for 50 to 60
per cent of the rolling resistance, a tyre manufacturer
must constantly break new ground when developing
compounds. ‘There is a tendency towards using ever
more complex compounds as well as the dual tread
compound, which involves either distributing two com-
pounds horizontally across the tread – in other words,
on the inner and outer area of the tyre – or vertically
using a so-called cap-and-base compound. Different
compound properties in conjunction with complex pro-
duction technology mean that the manufacture of tyres
Wish list: there are enormous demands on a tyre.
A tyre must be tested, tested and tested again before
it is approved for series production.
| MIXING know-how
1,2,3,4,5 7,8,9,10,11,12,13,14,15,16,...56
Powered by FlippingBook