Marangoni: Our retread would have had the same rolling resistance as a new tyre

Marangoni tested its own retreaded tyre following the procedure described in the ECE117 regulation applicable to new tyres, aware that this test did not represent a Type Approval for a retreaded tyre, but only for benchmarking purposes, the company recently affirmed.

In short, Marangoni S.p.A. wishes to follow up on the statement it issued on 5 June 2023, in which Marangoni said that that it is aware that there is currently no law/regulation on the labelling of retreaded tyres. According to Marangoni, the retread labelling regulation has been on the table for year with ETRMA and ETRTO and the European Commission. “The delay in the implementation of this regulation is having a negative impact on the so-called ‘Independent Retreading’ sector”, according to Marangoni.

The original press release referred to a tyre retreaded by Marangoni in its Rovereto (TN) plant with materials produced and designed by Marangoni itself in its Ferentino and Hamburg production sites. The retreaded tyre thus obtained was subjected to an experiment following the indications of the ECE117 regulation, which applies to new tyres, and in particular the Rolling Resistance part.

The Rolling Resistance (RR) coefficient of the retreaded tyre subjected to the above-mentioned test, was found to be in what is called the “Fuel efficiency class for C3 tyres” equal to “A”, as defined in EU Regulation 2020/740. This ECE Regulation117 defines the test procedure to which a new tyre must be subjected to, in order to calculate the friction coefficient Cr [N/kN], by measuring the friction force Fr [N] to which the tested tyre is subjected to, when a certain load [kN] is applied to it. Depending on the Cr value obtained from the ECE117 test, the level of Rolling Resistance of the new tyre is defined and applied on the label. These levels for tyres of category C3, i.e. Truck and Bus are: A if Cr<=4.0 or B if 4.1<=Cr<5.0 or C if 5.1<=Cr<6.0 or D if 6.1<=Cr<7.0 or E if Cr>=7.1 (see chart below).

Marangoni has tested a retreaded tyre following the same procedures applied to the new tyre only, without any intention of proceeding with any retread labelling activities, but only with a spirit aimed at continuous improvement of its products and to test the technical positioning with respect to a market with very strict and stringent rules such as that of the new tyre.

The tyre size used was 385/55R22.5. The tread profile applied on the casing is the Blackline RTL-FE 325XS ring, the ring tread compound was specially developed by Marangoni’s Research and Development Department in Rovereto, the casing used is top quality and was in the best RR level even when it was a new tyre.

Although the Marangoni Group has a Technical Centre within its own production site in Rovereto, thanks to which it is also able to conduct RR tests as specified by ECE117, in this specific case, in order to further validate the results, it has turned to a third party organisation to conduct this test, Prüflabor Nord GmbH in Brokstedt Germany.

Indeed, “Marangoni never intended to claim that its retreaded tyre has a Category A labelling, precisely because there is no regulation on the labelling of retreaded tyres, but simply wanted to communicate the result of the test used for new tyres, but conducted experimentally on its own retreaded tyre.”

In fact, Marangoni, as a member of the European associations ETRMA and ETRTO, has been an active participant for years in the technical working group on the “retread tyre labelling” project that is still being defined. In this regard, the company hopes that this project can finally be completed as soon as possible and has always confirmed its willingness to carry out whatever is required and necessary for the introduction of labelling also for retreaded tyres.

The company is focused on tyre sustainability with particular attention to the TBR and OTR tyre retreading supply chain and has always been committed to research and development of technologies, products and processes aimed at continuous improvement in the sector. “It is in this spirit that efforts are made to demonstrate that retreading a product such as a TBR tyre can achieve the performance levels of the best new tyres”, Marangoni representatives concluded.