BERLIN (Reuters) - The European Commission fears steps taken by Volkswagen (DE:VOWG_p) to refit polluting diesel cars may damage the vehicles' engines, the Spiegel magazine reported, citing unidentified staff at the European Union's executive branch.
Software updates carried out by Volkswagen (VW) could inflict greater stress on engine components, Spiegel cited a member of staff at the Brussels-based Commission as saying.
Commission officials are basing their concerns on feedback from experts at the "Vela" emissions laboratory in northern Italy, the weekly magazine said, without providing more detail.
The Commission could not immediately be reached for comment.
Germany-based VW denied its technical modifications would cause damage to the cars.
"The software update will have no adverse influences on (fuel) consumption or the durability of the engine and its components," a company spokesman said.
EU consumer affairs commissioner Vera Jourova has sought to ramp up pressure on VW to compensate European owners of rigged diesel vehicles and has asked the carmaker for guarantees its technical fixes will work.
"We need VW to guarantee, in a legally binding way and without any time limit, that the repairs will work and do not have any negative impact," a Commission official told Reuters on Monday.
Germany's KBA motor vehicle authority has so far cleared more than 5 million diesel cars affected by VW's emissions-test cheating scandal for repair. Approval by the KBA is valid for countries throughout Europe where 8.5 million cars are affected.
VW group models with 1.2-litre and 2.0-litre engines only require a software update on pollution control systems, whereas about 3 million 1.6-litre engines, besides the software update, also require a mesh to be installed near the air filter.