Some 10 vehicles examined in the past fortnight by a mechanic after their owners reported engine trouble were found to be running on low quality petrol.
The matter came to the attention of The Sunday Times after a reader complained that his engine was "knocking and stalling" as he drove to work. After two hours of thorough testing, his mechanic pinned down the fault to petrol with low octane content.
"The car started and drove well after the mechanic poured fuel additive that contained a high octane level," the reader said, insisting he was more concerned about the risk of causing an accident than the state of his vehicle.
The mechanic told the newspaper he had diagnosed a number of cars in the past two weeks with similar problems.
Petrol comes with an octane rating, which is a measurement of the fuel's tendency to burn in a controlled manner rather than erratically. The higher the octane rating the more efficient the engine. A low octane rating can lead to fuel being burnt inefficiently and, worse, causing the engine to knock.
Enemalta has denied it was to blame for engine trouble experienced by the reader. A spokesman said when contacted that unleaded petrol had a minimum octane rating of 95 and there had been no change in the composition of fuel over the past few months.
This is standard fuel found in other European countries, where it is also possible to find petrol with higher octane ratings.
"Enemalta carries out a full analysis on the fuel it imports, including petrol. This analysis is carried out by an independent, internationally recognised laboratory, Saybolt. For years, all Enemalta fuels have been found to be fully compliant with European specifications, to which these fuels are imported," the spokesman said.
Enemalta is still the only importer of petrol and diesel sold at petrol stations despite market liberalisation. When answering the reader's complaint the corporation said it was responsible for the fuel up to the point of delivery at petrol stations.
Enemalta told the motorist his complaint had been passed on to the Malta Resources Authority for further investigation.
"What happens at the service stations is the responsibility of the Malta Resources Authority and they have been informed about this report for their action," Enemalta said.
ksansone@timesofmalta.com