APRIL 2019 57TECH TALK
NG
T a way of making it easier for consumers to understand
w yres they are buying; the look similar to the labels
y g g machine. The label shows fuel effi ciency, wet weather
d the scale runs from A to G, with D not being used.
T ng straight from a C grade tyre to E makes it clearer that
t g g and, therefore, it’s easier to distinguish a better tyre that’s
g g g g, from a far worse one that gets an E.
Y
’s rolling resistance; the lower this is, the less energy
y better your fuel economy. The diff erence between an
A y approximately 7.5% or six litres of fuel for every 625
y dds up over the life of a tyre.
ERFORMANCE
T els on wet roads and the ratings are based on two
d mph measuring braking performance. Once again
t g e diff erence in stopping distance between each grade
ns that the diff erence in wet braking performance
G-rated tyre is 18m, roughly four car-lengths.
O S L
T g g g as it doesn’t relate to how quiet a tyre is from inside a car
y se when a car passes by and it’s more to do with noise
yone inside the car. However, it’s reasonable to assume
t ing would also likely be a little quieter inside the cabin
g g neral. The diff erence between one black wave and three
g ecause of the scale on which dB operates, means a tyre
w g four times noisier than a tyre with just a single wave.
NEXT MONTH
d why they’re not just for snowy conditionsEU TYRE LABELLING
This was introduced in 2012 as a way of making it easier for consumers to understand
what they can expect from the tyres they are buying; the look similar to the labels
you’ll fi nd on a fridge or washing machine. The label shows fuel effi ciency, wet weather
performance and road noise, and the scale runs from A to G, with D not being used.
The reason for this is that jumping straight from a C grade tyre to E makes it clearer that
there’s a big gulf between them and, therefore, it’s easier to distinguish a better tyre that’s
good enough to given a C rating, from a far worse one that gets an E.
FUEL EFFICIENCY
Fuel effi ciency is based on a tyre’s rolling resistance; the lower this is, the less energy
a tyre loses as it travels and the better your fuel economy. The diff erence between an
A-rated tyre and G-rated one is approximately 7.5% or six litres of fuel for every 625
miles travelled, so it defi nitely adds up over the life of a tyre.
WET WEATHER PERFORMANCE
This refers to the tyre’s grip levels on wet roads and the ratings are based on two
diff erent tests conducted at 50mph measuring braking performance. Once again
the D rating is not used and the diff erence in stopping distance between each grade
is approximately 3m. This means that the diff erence in wet braking performance
between an A-rated tyre and a G-rated tyre is 18m, roughly four car-lengths.
NOISE LEVEL
This rating is slightly misleading as it doesn’t relate to how quiet a tyre is from inside a car
but instead refers to drive-by noise when a car passes by and it’s more to do with noise
pollution than the comfort of anyone inside the car. However, it’s reasonable to assume
that a tyre with a lower noise rating would also likely be a little quieter inside the cabin
as it’s producing less noise in general. The diff erence between one black wave and three
equates to roughly 6dB which, because of the scale on which dB operates, means a tyre
with a three wave rating will be four times noisier than a tyre with just a single wave.
Winter tyres, and why they’re not just for snowy conditions