"However, the authorities have a different view, alleging that motorists were being misled by oil company advertisement and were wasting money on unnecessarily high octane petrol. Officials have calculated that motorists are wasting almost two billion baht a year on high octane fuel which contributes to the economic problems of the country as a whole. Technical arguments aside, local oil refiners have an economic motive in opposing the new grades. New oil refineries, including those of Thai Oil, Rayong Refinery Co and Esso Thailand Plc, have invested heavily in the past on units which produce high octane petrol. Producing lower octane petrol will mean lower returns on investment for refiners as those products yield lower prices."
"Once the capacity has been met, the committee will ask the government to stop importing methyl tertiary butyl ether (MTBE), an octane-boosting additive in petrol, because ethanol itself is also an octane booster. Thailand spent 4.4 billion baht last year on MTBE imports to blend with petrol in proportions of between 5.5% and 11%."
"The higher octane level helps reduce the knocking effect in an engine.But higher octane levels require more benzene additive, the material that has raised health concerns. Earlier this week the Journal of the National Cancer Institute reported in the United States that a study of 75,000 Chinese workers showed benzene was found to increase the risk of leukaemia and other blood disorders."