Recently I saw a new kind of fuel (octane 95) in the gas stations in Bangkok (sorry, can't recall its name). It sold a but chipper compare to the normal unleaded 95.

Maybe someone can point out the usage differences, if any.

P.S. My car is Nissan Sunny Super Neo 1,6 cc, auto-gear - which gas is better to use, and why?

The gas you're referring too may be what is call "gasahol"...nothing more than gasoline mixed with a bit of alcohol. It's a few baht cheaper than what is called "gao-har" or "95" for regular unleaded gas. My brother-in-law says cars can handle gasahol just fine but for an older car I'm not so sure. Alcohol if I recall burns at a higher temp than gas however if the amount of alcohol is small, it may not make much of a difference. The 95 octane is what I use in my old Toyota and is probably the best for these small cars....particularly older ones which may have some engine wear. The higher the octane, the fewer the "knocks" produced in the engine by insufficient combustion.

Check with the main dealer for you make of car.

They will be able to advise you on whether to use gasahol.

Search the web for Auto forums, groups etc. and ask the experts. Using the wrong fuel long term could prove too costly as a lot of internal engine damage can be done.