Aston Martin DB 9 2010 Manual page 221

Damage
Tires should be examined at regular intervals for wear and damage.
Inspect the tire treads and sidewalls for damage, i.e. bulges in the
tread or the sidewalls, cracks in the tread groove and separation in
the tread or the sidewalls. If damage is observed or suspected have
the tire inspected by a tire professional.
Stones or other objects which have become lodged in the tire treads
should be carefully removed.
Flat Spots
It is a characteristic of high performance tires that temporary flat
spots' may develop if the vehicle is left standing in high or low
ambient temperatures for any length of time.
These 'flat spots' will manifest themselves as minor vibrations when
the vehicle is first driven from cold. As the tires warm up to operating
temperature, normal tire shape should be restored and the vibrations
cease. If vibrations persist, consult your Aston Martin Dealer.
Age
Tires degrade over time, even when they are not being used. It is
recommended that tires generally be replaced after six years of
normal service. Heat caused by hot climates or frequent high loading
conditions can accelerate the aging process.
State or local regulations on tire life may apply.
New Tires
New tires should not be installed to the front wheels in combination
with worn rear tires, as rear end stability will be affected. When new
tires are required consult your Aston Martin Dealer for advice if the
rear tires are also worn.
Each wheel and tire unit must be balanced dynamically to make sure
of efficient steering, optimum tire wear and maximum ride comfort.
Because of the potentially high speeds, it is essential that wheel
balancing is carried out when new tires are installed.
'Running-In' New tires
When new tires have been installed, speed should be limited,
particularly during the first 50 mile (80 km) or so of driving. Fast
cornering, hard braking, and harsh acceleration should also be
avoided during this period.
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