A different tyre size is registered together with the wheels: document (1) or (2). Tyres must always meet the legal minimums.
Inspection neededYes
Certified part neededYes
What you need to know
Document (1) or (2) is required.
Document (1): report from an approved technical service on the compliance of the modifications with the legal framework (individual approval).
Document (2): conversion certificate from an automotive professional with the chassis number, a precise description of the modifications and references to the technical reports (TÜV, Gutachten) of the parts, plus copies of those reports.
Tyres need enough load capacity and a sufficient speed index, visible grooves over the whole tread, no visible cord and no deep cracks in the sidewalls.
The main grooves must be at least 1.6 mm deep (1.0 mm for mopeds and trailers).
M+S tyres with a lower speed index are allowed if the maximum speed is displayed in the cabin (Arrêté grand-ducal of 23 November 1955, art.
21).
A combination of modifications that influence each other (for example wheels and suspension, spacers and suspension, power and wheels) always needs document (1).
The check must happen before the vehicle goes back on the road, or at the latest before the next technical inspection and never more than 2 months after the modification.
If the change is not entered in the 'remarques' field of the registration certificate, the inspection records a major defect.
If the documents are incomplete, the vehicle must go to an approved technical service for a compliance report.