Switching to more viscous (semi-synthetic) oil is in some cases recommended for vehicles older than 10 years and/or with more than 200,000 km traveled. It is certainly not mandatory and is an option to reduce the maintenance costs of vehicles that have increased oil consumption due to larger gaps in the engine assemblies, of course, as long as it is within the limits set by the manufacturer. For more information, visit the Advice & Proposals section.