My 2006 Mazda3 2-litre sport is supposedly ok with any of the locally available petrol options as well as gasohol 95 or even 92. I would like to understand the criteria on which I should be choosing between them. Presumably the price difference will go with performance (speed and/or acceleration); but leaving that aside and assuming the car is driven in a leisurely way - mostly in town - which fuel would be best from the point of view of the engine's wear-and-tear?

I would not expect your 2006 to be E20 compatible, so lets leave it out. Most TH japs worked to become E20 compatible early 2008

gasoline or gasohol E10, 91 or 95, the cheapest one your engine accepts, will provide lowest fuel costs. As this is a simple engine without knock sensor ECU does not adjust for higher octane whenever used.

I would not expect your 2006 to be E20 compatible, so lets leave it out. Most TH japs worked to become E20 compatible early 2008

gasoline or gasohol E10, 91 or 95, the cheapest one your engine accepts, will provide lowest fuel costs. As this is a simple engine without knock sensor ECU does not adjust for higher octane whenever used.

Totally agree. My 2008 Mazda 3 was the first model compatible with E20.

I also agree to use the cheapest fuel suitable for your car. IMHO it is a fairy tale that (modern) engines would have a better performance with higher octane figures. I mostly use E20 and E10 (91 Gasohol), but also tried 91 and 95. I couldn't note any difference in performance or fuel consumption.

After 3 years and more than 90'000 kilometres, the engine is running as smooth as at the beginning.

But we will replace the current Mazda with the new Mazda 3 with 5-speed automatic. In about 2 year, we hopefully would change again to the new Mazda CX-5, which will come to Thailand...!

IMHO it is a fairy tale that (modern) engines would have a better performance with higher octane figures.

Absolutely true for mainstream models, but high performance cars show a noticeable improvement as octane goes up and Ethanol content is replaced with Benzene. But they're the 1 percentile - for everything else, use the cheapest fuel your engine is designed to support.

Any idea if a Toyota Prius Hybrid can take the Gasohol 95 E 20?

Thank you for the information.

Shell has a slightly pricier option (I forget what they call it) of their gasohol fuels; from what you have said I presume this is of no benefit to my car.

I have to say that the car did give better mileage per gallon on petrol (benzene, as they call it here). But all in all it'll probably work out cheaper if I use gasohol 91, and based on your info I shall do that now. (Until now I'd been switching back and forth between petrol and gasohol 95).

Thanks for the info - based on your own Mazda experience.

I will be selling my Mazda for a new car when the next Bangkok Motor Show comes around next year. I was curious as to what you might advize as the most productive ways of selling my car - websites or other ways, given that I won't necessarily be looking for a quick sale & my car is not on finance or anything of that sort.

I would not expect your 2006 to be E20 compatible, so lets leave it out. Most TH japs worked to become E20 compatible early 2008

gasoline or gasohol E10, 91 or 95, the cheapest one your engine accepts, will provide lowest fuel costs. As this is a simple engine without knock sensor ECU does not adjust for higher octane whenever used.

Totally agree. My 2008 Mazda 3 was the first model compatible with E20.

I also agree to use the cheapest fuel suitable for your car. IMHO it is a fairy tale that (modern) engines would have a better performance with higher octane figures. I mostly use E20 and E10 (91 Gasohol), but also tried 91 and 95. I couldn't note any difference in performance or fuel consumption.

After 3 years and more than 90'000 kilometres, the engine is running as smooth as at the beginning.

But we will replace the current Mazda with the new Mazda 3 with 5-speed automatic. In about 2 year, we hopefully would change again to the new Mazda CX-5, which will come to Thailand...!

You will get better mileage out of straight gas\benzine due to alcohol having less btu's per litre. With modern engine management systems most cars will run no differently with 91 or 95 in the tank, Ive never seen a car in thailand with enough horsepower to justify anything except green 91 lol.

Thanks, everyone. I will now be switching to gasohol 91. But to finally nail this, can I take it that, leaving aside power/performance, there is no greater wear and tear or other disadvantage to the engine by moving down from 95 to 91?

Thanks, everyone. I will now be switching to gasohol 91. But to finally nail this, can I take it that, leaving aside power/performance, there is no greater wear and tear or other disadvantage to the engine by moving down from 95 to 91?

The ethyl alcohol in gasohol will rot rubber components in the fuel system of older engines. The fuel pressure regulator in my Land Rover V8 was destroyed in this way.

BTW using edible products as a feedstock for ethanol fuel is a crime in my view.