Choosing the right tire is important,
but as Total 911 reports, there are many factors to bear in mind
The significance of correct tires and the
effect differing rubber will have on handling, braking and grip characteristics
in both wet and dry conditions should never be neglected. While we are aware
that worn rubber is ‘bad’ and premium tires are ‘better’ than economy, the
truth is that many vehicle owners underestimate the impact the right or wrong
tire choice can have on the driving experience – never mind your own life
expectancy!
The
significance of correct tires and the effect differing rubber will have on
handling, braking and grip characteristics in both wet and dry conditions
should never be neglected
After taking a trip to Continental Tires’
facility in Hannover, enjoying over nine hours of testing on various surfaces
in various conditions and with every conceivable setup of tire, there are a few
discoveries regarding tire wear that should be elaborated on.
First, never underestimate the importance
of fitting a premium tire or having the correct pressures. We tested a plethora
of cars fitted with multiple amalgamations of premium and economy rubber
alongside various tread depths on various surfaces and tracks, and the results
were astounding.
We began with the wet circle test, which
highlights the effect of leaving a motorway onto a curved slip road. We were
placed in four identical cars with a mixture of economy and premium tires – all
we had to do was get our foot down and see how the car reacted.
Not one of the journalists who took this
test will ever ft economy tires again. Not only did budget tires have hugely
underwhelming grip levels (we are talking a difference of 45kph versus 80kph
around what was fundamentally a roundabout) before they lost traction, it was
the immediacy with which they gave up the fight, with no progression or
feedback; just ‘on’ and ‘off’. Although it was no doubt fun on track to ‘test’
a car with premium fronts and economy rears, it would be downright dangerous on
public roads – and not something you should chance on.
Continental
espouses the virtues of premium tires
When an economy tire loses grip, it happens
with no warning at lower speeds, and there is little opportunity to recover,
even when you’re expecting it. Apart from this lack of grip, the inability to
stop (over four car lengths, some 18 meters further at 50mph than a Class A
tire!) as well as differences to sharpness and responsiveness to steering
inputs are worlds away from a premium tire.
As many Porsches run different widths front
and rear, the oft-seen shortcut of swapping your rears over to the front is thankfully
impossible, but as you would expect, having matching, quality rear tires is
imperative. Pairing premium front tires with budget rears may be fun on a
closed track with over steer just a toe edge away, but on the road it’s a
different story. Budget tires have such an immediate transition from grip to no
grip and are so limited in the wet that a car becomes snappy and unpredictable
even at sensible speeds. With such a distinct clash in behavioral
characteristics it will never enable a driver get the best from the chassis
beneath them. The message here is to invest in premium rubber for your coveted
Porsche.
Here,
you can see more closely the layering of the textile cord body and nylon cap
ply of a tire
Another test was aquaplaning, where we
drove through a pool of water 1.5 inches deep round a curved road at various
speeds. At 8mm (full tread depth) the car held its line. With premium tires at
80kph and 5mm of tread depth, the car shifted about a foot off line – scary,
but not life-threatening. The biggest shock, however, came at 1.6mm, which is
still a legal tread depth in the UK. At this speed, the car literally moved
eight feet over in an instant, which would easily be enough to send you into an
oncoming lane with no means of escape in the real world. Continental themselves
explained that at 1.6mm, even premium tires are only 55 per cent as efficient
and take a further 13 meters to stop in wet braking tests. With all control of
the car immediately taken away, the knee-jerk reaction is that of fear. It does
make you question the current UK legislation but regardless of the law, at
below 3mm you are on dangerous ground. Although this may be obvious, what may
surprise is the wider the tire, the worse aquaplaning can become.
The answer, then, is to ensure that
especially in the wet, your rear tires have at the very least 3mm of tread,
because even when you know what’s about to happen you still can’t stop it, and
efforts to recover are simply too little too late.
The
fact is that premium tires offer impressive levels of grip in both wet and dry
conditions, and for road use more than you will likely ever need
Having established why we all need to run
premium tires and why at 3mm you are better off investing in new rubber, the
next important decision is which tries to choose and what Porsche’s ‘N’ rating
system means. From my research, it does appear that many OPCs will insist that
all tires are ‘N’ rated, so it is worth checking with your dealer if you are
under warranty. However, I have found no evidence that an N-rated tire performs
any better than one without such markings, and that you would not be covered by
your insurance in an accident – many believe the N system is simply a marketing
tool from Porsche, as a lot of manufacturers recommend a different letter
(Ferrari K, Bentley B, Mercedes MO etc).
The fact is that premium tires offer
impressive levels of grip in both wet and dry conditions, and for road use more
than you will likely ever need. There is a balancing act, however – the better
the grip and softer the compound, the faster the wear. Perhaps that is the main
factor to bear in mind.
