Cardinus Risk Management
Safe Driving Programme
Getting the most from your
tyres
How did you choose your car - sporty performance? Excellent
ride and handling? More power and performance? Assisted
braking in emergencies? Good fuel consumption?
One component that significantly affects all the above
elements - the tyres fitted to your car. Tyre size, width,
compound and tread pattern all play a part. There are many
choices – all designed by the manufacturer to complement
and deliver a balance of features as above. Original
equipment tyres are selected for the optimum compromise for
you – when you have tyres replaced, your choice of
replacement tyre can maintain or compromise the results.
Have you ever wondered why racing cars have no tread
pattern – as they do in dry conditions? Tread patterns are
there to disperse water from the road surface and sustain
good contact– up to 12 gallons a second with some new tyres.
How much water do they remove when the tread depth is
down to 1.6mm, which is the legal minimum indicated by the
Tread Wear Indicators in the grooves of your tyre? Slow down
in wet weather.
6. 7. 8. It's not just hot air!
1. 2. 3. 4. 5. Tyre pressures – too low by more than 10% can
increase rate of wear by more than 30% – increased
flexing causes heat which softens rubber, increasing the
rate at which it wears away. Manage the risk! Check the
pressures carefully and frequently. After a party,
balloons go down in a few hours or a few days, so why
do we trust our expensive balloons to last for five to ten
months? Remember also the spare tyre – it won’t help
you if deflated.
Tyre pressure – too high. Tyres are part of the
suspension system; hard tyres put additional strain on
other suspension parts and promote risk of premature
failure. Manufacturers recommended pressures are
chosen with this in mind.
Repetitive strain injury? Speed humps frequently
taken too fast can cause tracking or suspension faults
(such as where the front wheels are not running parallel
to each other). Most of the tyre appears legal - but the
inner edge can be below the legal limit, with tyre body
cords exposed. You must check the whole tyre width
(watch your fingers on the steel cords!). Manage the
risk! Speed humps are there to slow you down for
safety.
Servicing – don’t just trust the garage to check
your safety. Some garages don’t bother at all (if tyre
pressures look ‘about right’) – time is money, shortcuts
can mean more services completed in a day. Other
garages get the tea boy or apprentice to do it – does he
really bother to find out the correct pressure for your
car/model/tyre size? Most garages are very
conscientious, but how do you know where you stand if
you don’t check for yourself? Manage the risk!
Would you run a marathon with a Wellington on
one foot and a Sandal on the other? Yet how many
people drive their car hard – with four different tyres
fitted? If you want safe and predictable handling then
give the car a fighting chance. Manage the risk – fit the
correct matching tyres – or modify your driving style to
suit your tyre choices.
9. 10. 11. 12. Tyre tread is designed to disperse water. New,
top quality tyres can disperse up to 12 gallons of water
per second at 60mph or more on a flooded road – that
ability diminishes considerably as tread wears down,
also the type of tread pattern itself can make a
significant difference. New tyres have around 8mm or
more of tread. At 1.6mm would you want to do 60 mph
in heavy rain? Manage the risk – change the tyres – or
change your driving style to reflect wearing tyre tread.
Tyre compound – very soft tyres grip the road well as
they mould into the surface, but, they wear away too
quickly compared with hard tyres, which last much
longer, but have correspondingly less grip. When you
change your tyres – will they be better or worse than
the old ones? How will you know? Just because they
look the same, you cannot be sure. Drive to manage
the risks.
Punctures and blowouts (sudden complete deflation)
are rare with modern tyres but one of the most
common causes is kerbing damage (front left tyre due
to poor parking, or rear left due to kerbing on tight
urban turns). How well do you check after someone
else, such as garage or spouse have driven your car?
Do you have a space-saver spare wheel? If you
do, it is usually limited to 50mph for no more than 100
miles (check the handbook). As it is so much less wide
and deep it will affect extreme handling (braking and
swerving hard is not recommended!) If you get a
puncture, you need to be aware of the limitations on
journeys.
Some cars now have directional tyres – an arrow
on the sidewall shows tyre rotation direction. There was
a time when changing tyres corner-to-corner was
advised to even up wear patterns, but this could cause
a problem with directional tyres. Are yours fitted
correctly?
Run-flat tyres – are increasingly fitted to save the
need for changing tyres after a puncture and can
usually be driven safely and gently to a tyre centre (but
once again with mileage restrictions). Punctures can be
repaired, sometimes within the first few miles –
however if you drive for extended distances at higher
speeds, adverse tyre damage will require a new tyre
and you will be a captive customer forced to pay a
higher price with no choices. Know your tyres and their
limitations.
Winter tyres – or more appropriately ‘cold weather
tyres’. Typical ‘all-season tyres’ as fitted to almost all
UK vehicles have to be able to cope with all conditions –
however, in very cold weather the tyre compound loses
resilience and therefore loses some ability to grip the
road or deal with snow, ice etc. Winter tyres have a
softer compound to deal with lower temperatures and a
different tread pattern to deal with snow/ice. Such ‘cold
climate tyres’ are well suited for Scandinavia or areas
of Europe (e.g. Alpine areas) where very low
temperatures are maintained for extended periods –
however as soon as temperatures rise in our variable
climate in the UK, these tyres soften and begin to wear
far more quickly and can be very noisy. The
inconvenience of changing tyres often to reflect
frequent temperature variations and the problem of
storing the ‘other’ tyres far outweighs the benefit for
most British drivers.
Bonus checks
The costs?
Pressures – the correct pressure for your car may be shown
on the driver’s door pillar plate. If referring to the handbook
compare tyre sizes to the tyres fitted to your car – several
options may be listed, be sure to find the correct one (consult
your dealer for advice if in doubt.)
Cuts and splits – check the sidewalls; be sure to look at the
inside walls too. Check the rims, both inside and outside for
signs of damage.
Bulges – a bulge in the tread or sidewall is an indication of
structural tyre damage. Replace immediately before sudden
deflation in inconvenient circumstances.
Ignoring this advice and you compromise the safety of your
vehicle, its occupants and other road users.
Driving with low tyre tread depths, low pressures or tyres that
are damaged, risks three points on your licence per tyre.
Driving with four illegal tyres and many offences could mean
immediate disqualification, the end of your livelihood and
potential loss of life.
Manage the risks. Check your tyres
frequently. If in doubt – seek professional
advice.
Additional resources can be found in the ‘My Resources’ panel on your Cardinus Risk Management Safe Driving Programme
home page. If you have any further queries please email us at [email protected] or by phone on 01733
426015.