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This paper describes Hyundai's research and development work on a flexible fuel vehicle (FFV). The work on FFV has been conducted to evaluate its potential as an alternative to the conventional gasoline vehicle. Hyundai FFV described here can operate on M85, gasoline, or any of their combinations, in which the methanol concentration is measured by an electrostatic type fuel sensor. For that operation, a special FFV ECU has been developed and incorporated in the FFV. The characteristics affecting FFV operation, such as FFV ECU control strategy and injector flow rate, have been investigated and optimized by experiment. Various development tests have been performed in view of engine performance, durability, cold startability, and exhaust emissions reduction. The exhaust gas aftertreatment system being consisted of manifold type catalytic converter(MCC) and secondary air injection system has shown good emission reduction performance including formaldehyde emission.

An experimental study on performance, exhaust emissions and cyclic variations was carried out for gasoline, M100 and M85. To take the advantage of methanol's higher octane number, increased compression ratio was tried and its effect was investigated. A pre-ignition detector was installed to eliminate the possibility of pre-ignition damage. THC emissions from methanol were corrected by some assumptions in order to be compared with those from gasoline. Combustion pressure data were measured by virtue of a fast data acquisition system. From them, all data required for the investigation of cyclic variability were obtained. The coefficient of variations of 1MEP was applied as a criterion of lean misfire limit. Improved performance was achieved for methanol. The advantage on exhaust emissions, especially NOx and THC, was also confirmed. It was found that Pmax has close relationship with combustion durations and there is no noticeable connection between successive cycles.