Wheels and Tyres Guide - General Information

EU tyre label, categories

~4min read

Rolling resistance → Anchor

Wet grip → Anchor

Noise emissions → Anchor

Rolling resistance

Rolling resistance:

Defined as, energy consumed by the tyre in respect of the distance travelled.

Equates to the energy lost per defined unit of distance travelled.

The energy form can be described as the quotient of Newton meter (Nm) and distance travelled in meter (m). This then provides a rolling resistance as a form of force in Newtons (N). The rolling resistance of a tyre is then described by the coefficient of rolling resistance (also known as rolling resistance coefficient) cR:
cR =
FR
Z

c R - coefficient of rolling resistance

F R - force of rolling resistance

Z - weight of vehicle (sum of all wheel loads)

Objective

Reduction of rolling resistance

Reduction of fuel and CO 2

EU tyre label, categories

Evaluation

Structured in fuel efficiency categories from A to G

Category D is not used

Note The fuel efficiency category is listed in EU regulation (EC) No. 1222/2009, the tyre is then allocated to the respective category. The rolling resistance is established by the tyre manufacture via prescribed tests.

The lower the rolling resistance, the lower the fuel consumption.

A - Lowest rolling resistance = lowest fuel consumption
B - + 0.10 l / 100 km
C - + 0.12 l / 100 km
E - + 0.14 l / 100 km
F - + 0.15 l / 100 km
G - + 0.15 l / 100 km
EU tyre label, categories

Wet grip

Definition

The wet grip index G must be established for the wet grip. The wet grip index G is established using a deceleration test (distance required to decelerate from 80 km/h to 20 km/h) using a standardised vehicle on a wet slippery surface. The test uses a predefined standard reference test tyre (SRTT), with which the wet grip index G can be calculated. The calculation uses the mean fully developed deceleration (mfdd) produced.

The mean fully developed deceleration (mfdd) is calculated as follows:

mfdd =
231.48
S

S - the measured braking distance in metres between 80 km/h and 20 km/h

The wet grip index G is calculated as follows:

G =
mfdd of tyre to be checked
mfdd of standard reference test tyre

mffd - mean fully developed deceleration

Objective

Good wet grip of tyre

Greatly reduced bake distance

EU tyre label, categories

Evaluation

Structured in wet grip categories from A to G

Categories D and G are not used

Note The wet grip category is listed in EU regulation (EC) No. 1222/2009, the tyre is then allocated to the respective category.

The lower the wet grip index, the shorter the braking distance.

A - Lowest wet grip index = shortest braking distance
B - 3 to 6 m longer braking distance in comparison with category A
C - 3 to 6 m longer braking distance in comparison with category B
E - 3 to 6 m longer braking distance in comparison with category C
F - 3 to 6 m longer braking distance in comparison with category E
1 - The braking distance between categories A and F can be more than 18 m when undertaking an emergency stop at 80 km/h.
EU tyre label, categories

Noise emissions

Objective

Reduction of pass-by noise

Reducing noise emissions

Evaluation

Measured on outside of vehicle only

Divided into three categories

EU tyre label, categories
Three black arcs indicate the worst performance. The tyres produce a rolling noise that lies below the current limit according to EU regulation 2001/43/EG. The limit lies above the limit that has been set for from 2016 according to regulation (EG) No. 661/2009. Two black arcs: The tyre noise limit lies below the limit that has been set for from 2016 according to regulation (EG) No. 661/2009. One black arc: The tyre noise limit lies below the limit that has been set for from 2016 according to regulation (EG) No. 661/2009, by at least three decibels. Note Reducing the noise level from two arcs to one arc equates to 3 dB, which halves the noise level. Note, the external rolling noise of the tyre does not always correspond with the noise in the vehicle interior.
EU tyre label, categories

Test yourself

A quick Volkswagen Golf quiz: every answer comes with an explanation and a link to the manual page.