Honda Motor has developed a new flexible fuel vehicle (FFV) system that enables petrol engine-based power plants to operate on either 100% ethanol or a wide range of ethanol-petrol fuel mixtures.


In late 2006, the automaker plans to begin sales of FFVs in Brazil, where bio-ethanol is popular.


Up to now, variations in the ratio of ethanol-to-petrol have affected low-temperature start-up performance, and caused variations in air-fuel ratio and engine output. This has made it a challenge to maintain stable dynamic performance, fuel economy and emissions levels.


The new Honda system adapts to different ethanol-to-petrol ratios by estimating the concentration of ethanol in the ethanol-petrol mix in the fuel tank based on measurements of exhaust gas concentration in the vehicle’s exhaust system.


This provides the flexibility to adapt to ethanol-to-petrol ratios of between 20% and 100%, while achieving outstanding fuel economy and dynamic performance on a par with a 100% petrol-powered vehicle.


In addition, a cold-start system utilising a secondary fuel tank ensures reliable starts even at low ambient temperatures. Such technology is already used on a number of rival automakers’ FFVs already on sale in Brazil.


Bioethanol fuel, as used in Brazil and other countries, is made from plant sources such as sugar cane. Because plants absorb CO2 via photosynthesis, the amount of CO2 released into the atmosphere from burning bioethanol fuel does not increase atmospheric CO2. This makes bioethanol fuel an effective means to combat global warming as well as an alternative to petroleum, Honda said.


Honda already builds the Civic sedan and Fit (Jazz) hatchback at its own assembly plant in Brazil. The Civic FFV’s 1.8-litre I4 engine develops 103kW/140PS (petrol: 102kW/138PS) while the 1.4-litre I4 Fit engine makes 61kW/83PS on ethanol and 59kW/80PS on petrol.