The nation’s regulatory agency said that samples of gasoline show lower levels of methylcyclopentadienyl manganese tricarbonyl, known as MMT.
The additive is controversial, and some motorists said that the chemical has damaged the engine of their vehicles.
In August the regulatory agency, the Autoridad Reguladora de los Servicios Públicos confirmed that gasoline from the monopoly Refinadora Costarricense de Petróleo contained the chemical. The agency asked the state refinery to suspend importation of gasoline with the additive. The issue was raised first by a television news show.
Recent tests showed only one sample had higher levels of MMT than vehicle manufacturers specified, said the agency.
In August, analyses showed that there was an average of 23.4 milligrams per liter of manganese in both plus and super gasoline. The average amount of MMT was 92.8 and 93 milligrams per liter at samples taken at a service station in La Garita. That was far in excess of the recommendation of the supplier, Afton Chemicals, a Virginia firm, said the agency. The additive is supposed to boost the octane of the fuel. The manufacturer’s recommendation is between 8 and 18 milligrams per liter.
The agency said it has 92 complaints from motorists about damaged vehicles.