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# Know-How

UN Regulation 117

Rolling Resistance and Rolling Noise Limits for Truck and Bus Tires

Fast facts

  • UN regulation 117 was introduced in 2005 and amended to version 117.02 in 2011. In EU Member States and Norway it applies since 1 November 2011 (EC Regulation 661/2009).
  • The regulation (hereinafter called UN reg. 117) sets tire type approval limits for rolling resistance, sound and wet grip.
  • The limits and timings of introduction in Europe differ among tire classes (truck/ bus, light truck, passenger car), segments (replacement, original equipment).
  • NEW from 1 November 2017 for truck/ bus tires: OE tires for newly homologated vehicles must fulfill the R2 rolling resistance limit. This means roughly 20% lower rolling resistance than the previous R1 limit.
  • From 1 November 2020, OE tires for all vehicles entered into service must meet the R2 rolling resistance limit.
  • All new Continental developments (incl. winter tires) since 11/2016 already fulfill the new limits for OEM use.

In 2009, the EU decided to introduce type approval for noise, wet grip, and rolling resistance according to UN regulation 117. A new “big E4 number” was added to the tire sidewall to signify type approval for UN regulation 117 replacing the smaller e4-S numbers stepwise.

External Rolling Noise: S1 or S2

Wet Grip: W*

Rolling Resistance: R1 or R2

* not mandatory in all cases

Rolling Resistance and Rolling Noise Limits for Truck and Bus Tires

Every tire manufacturer must make sure that every tire sold in Europe and affiliated states falls within the sound and rolling resistance limit as defined in R117. Type Approval authorities issue the R117 certificate. This number will have to show on the tire’s sidewall including SxRx levels, e.g. as shown above “E4 023296 S2WR2”. See tables below for the stage 2 limits for truck and bus tires and for the introduction dates. All new Continental developments (incl. winter tires) after 11/2016 comply to “S2R2 / S2WR2”. 

EU Tire Label Classes for Truck and Bus Tires

Tires that fulfil the R2 limit are labeled at least D, for winter tires marked with the Alpine-Symbol (3PMSF) an E label is still possible.

With introduction of R2 the minimum rolling resistance is raised by 20%. Continental tires that are labeled with C or better therefore have at least another 7.7% better rolling resistance performance than required by the new R2 type approval limit. 

EU Tire Label Classes for Truck and Bus Tires

Continental Winter Tires

In wintry weather conditions Continental recommends fitting winter tires on all axles of trucks and buses, since standard tires reach their limits very quickly. Their suitability in winter is very limited on cold and damp, snow-covered, or icy roads, despite the M+S label that is required by most European countries. By contrast, commercial vehicles fitted with tires that are genuinely designed for winter use can travel more safely, reliably, and economically. For winter tires to be labeled with the 3PMSF symbol, they have to pass a test legally defined in the ECE 117.02, which confirms their superior traction and braking performance on snowy roads. Continental Scandinavia winter tires marked with the Continental snowflake symbol easily outperform M+S tires and significantly exceed the requirements of the Alpine-Symbol (3PMSF).

Traction comparison tests carried out by Continental with standard M+S tires strikingly demonstrate that, when used on all axles, Continental Scandinavia tires for trucks shorten the braking distance on snow at a speed of 50 km/h by nearly 10 meters. At the same time, they also increase traction by up to 40% in extreme winter conditions. Continental tires thus meet and exceed all regional regulatory standards - from long-distance motorway trips spanning several European roads to regional short-distance driving. 

Limits in dB for External Rolling Noise

Truck and Bus Tires


in dB (A)


Stage 1

= S1


Stage 2

= S2

Normal Tires*

Severe Snow **

Special Use Tires
(i.e. Offroad Tires)
Traction Tires

-+2 dB (A)

* Limit also applies to Tires marked with M+S

** Tires which have passed the snow test and bear the Alpine-Symbol (3PMSF)

Limits for Rolling Resistance

Rolling Resistance is expressed by a Coefficient: The RRC is defined as RR force (N) divided by the tire load (kN).

Tire Class


Max. value* (N/kN)


Max. value* (N/kN)

C1 Passenger Car1210.5
C2 Light Truck, Light Commercial10.59
C3 Heavy Truck, Heavy Commercial86.5

*Snow tires for use in severe snow conditions (3PMSF) may have 1 N/kN more