KATHMANDU: Sale of low-octane petrol, coupled with the mixture of solvents that degrade petrol’s quality, continue to pose a threat to the efficiency and longevity of motor engines. Nepal Oil Corporation, the state-owned entity responsible for the import and distribution of fuel in the country, is currently supplying 88-octane petrol. While, the petrol engines perform their best when run on 91-octane fuel. Despite a litany of complaints over the purity of petrol after numerous petrol engines faced seizure or suffered efficiency, the government is yet to address the issue. Prem Lal Maharjan, president, National Consumers’ Forum, complained that 88-octane petrol worsened by solvents had resulted in detonation, the bizarre knock experienced in a petrol engine due to an anti-ignition factor in fuel. “Higher the octane value, lower the anti-ignition portion in fuel. It is a serious concern for urban consumers who have petrol vehicles at their disposal,” he said, explaining that there are three categories of solvents. “Solvent-90, solvent-60 and solvent-30 are available in the market. The unscrupulous traders often opt for solvent-30 to mix it with petrol for huge profits.” Such solvents, which reduce the octane value, are compatible with the fuel colour. Mukunda Dhungel, NOC spokesperson, said they would import 91-octane from 2010. He said consultations with Indian dealers were underway. Fuel price varies depending on the octane value. Saroj Pandey, president, Petroleum Dealers’ Association of Nepal, denied charges that they were mixing fuel with extraneous materials.