Tyre regrooving: revamp tread patterns to prolong tyre life

⁽¹⁾ Compared to a worn, non-regrooved Michelin tyre. Information based on the recommendations made by the French tyre manufacturers’ federation (TNPF) in 2019, according to which the regrooving of worn tyres increases tyre life by using all the available rubber

⁽²⁾5.4% save in fuel consumption: internal study carried out at the Michelin test tracks in Ladoux (France) on 5 May 2021, under DEKRA supervision (report No. 21CPAEXT-030). For the comparison between new tyres and regrooved tyres (R5 mm), two identical Volvo FH500 trucks were used, fitted with 315/70 R 22.5 Michelin X^® LINE ENERGY™ Z2 & D2 tyres and each towing a fully loaded (40 tonnes). Schmitz Cargobull trailer fitted with 385/55 R 22.5 Michelin X^® LINE ENERGY™ T tyres at identical pressures (8.5 b, 7.5 b and 9.0 b). Results may vary depending on weather conditions, road type, tyre size and driving style.

⁽³⁾ On wet ground, regrooved tyres offer approx. 10% greater transverse grip and traction compared to the same worn tyres. Internal study carried out by Michelin on a polished concrete track at Ladoux (France) in 2010; results may vary depending on the actual conditions of use.

⁽⁴⁾  The CO₂ savings from the Michelin multi-life model, are accentuated thanks to the fuel savings linked to regrooving (up to 5.4%⁽²⁾). According to a study under real conditions of use (using 315/70 R 22.5 tyres fitted to the drive and steering axles of a 4x2 truck used for international and national long distance, that have exceeded 50% wear), the average mileage for Michelin X^® LINE ENERGY™ Z2 and Michelin X^® LINE ENERGY™ D2 tyres is 232,200 km before regrooving* (*Michelin internal source and calculation, based on measurements taken by the Michelin teams during customer inspections on 488 axles, in Austria, Belgium, Croatia, the Czech Republic, France, Germany, Greece, Hungary, Italy, the Netherlands, Poland, Portugal, Romania, Serbia, Slovenia, Spain, and Turkey, over the period from 2020 to 2023), with a simulation based on the results collected suggesting extrapolation of the lifespan until 3 mm remains. The results may vary depending on the weather and road conditions. The view is that our tyres travel up to 25%⁽¹⁾ further thanks to regrooving, i.e. 58,050 km (232,200 x 25%). The fuel savings are calculated over the distance travelled by the regrooved tyres (58,050 km) at an average consumption of 29.5 L/100 km for new tyres and 27.91 L/100 km for regrooved tyres (source: DEKRA report No. 21CPAEXT-030). 29.5 x 5.4%, i.e., a saving of 1.59 L/100 km for an articulated truck and tri-axle trailer (thus 12 tyres) Consequently, there is a saving of 0.13 L/100 km per tyre (1.59 L/12), i.e., 0.13 L x 58,050 km/100 = 77 litres of fuel saved when driving on regrooved tyres, thus a saving of 77 litres of diesel x 3.24 kg of CO₂ = 251 kg of CO₂. The emissions factor of 3.24 kg of CO₂ for 1 litre of diesel comes from the life cycle assessment conducted by ADEME for pure diesel. It includes emissions during the diesel production stages (17%) and during its combustion (83%). Source: ADEME. Base Empreinte, Étude Carbone, Version 22.0.0, 02/08/2022. Thus 77 x 3.24 kg of CO₂ = 251 kg of CO₂.

⁽⁵⁾ Michelin study conducted on 1 million tyres provided for Michelin Remix retreading in 2008 and 2009. The difference in the approval rate between retreaded regrooved tyres and retreaded non-regrooved tyres is below 0.2%.