Gasohol is actual a mixture of gasoline and alcohol, mostly ethanol. For the time being, Thailand gasohol is a mixture of 90% gasoline and 10% ethanol, coded E10. The mixture proportion is to be increase in later time. When? I don't have any idea. Can't read Thailand that good. Can't read Thailand at all!
Gasohol has been proven to have some disadvantages against gasoline. I experience 2 weird thing on my ZX10R while riding to Phuket early this month. Mr. Gibsi told me he felt his bike, which is the Kawasaki Z750s, underpowered after clocking 300km from Danok. I didn't really felt the effect since our riding pace are between 120-140km/h.
The first thing to be notice on the fuel is the color, looks like a Shell V-Power from the naked eye. It's set your mind that this fuel is already different.
The second thing is when we fuel up in Trang, I exposed my bike to a direct sunlight, with the temperature I guess that day felt like 32°C-33°C (or maybe higher). I've always fill up to the fuel reaches to the tank's lip. After just a few minutes, the fuel came out from the overflow pipe. This experience showed me the fuel is easily evaporated. An alcohol nature. From there I kept watch on where I parked my bike and always looking for a shaded area.
The third thing is while we on our way back to Danok from Phuket, we're on the highway 44 which is a long stretches of 100km going to Surat Thani. All five of us has a blast on our bike and my bike topped 300km/h with some effort to do so. On the 6th gear, when doing 260km/h, it felt like forever climbing to 300km/h. My bike are on a standard setup, and it never felt like this. So it is noticeable that the bike has loss some power. I do blame on the fuel. This prove to be right when we are back in Malaysia, after fueling at Petronas Bukit Kayu Hitam, then fill up again at Bukit Merah, the power come straight back again.
When we fill up at Pang Nga Shell Station on our way back, as always, I was just looking at the octane numbers. Kawasaki recommended a gasoline 95+ Octane and above for the ZX10R. So a pump with label 95 should do fine. Here, the pump attendant lift up the pump and said "Gasohol?". I'm a bit puzzle myself, if not, why do the pump attendant prompt me it's gasohol. Isn't it just a fuel? We didn't have any gasohol here, so what the heck gasohol actually is I really don't know. After safely arrived back only I did some digging on gasohol.
Digging on the web, there are no superbikes design to cope with gasohol. Manufactured vehicle for Thailand are actually design and approved to used gasohol since 1995. But bikes which are imported from Japan and Europe doesn't fit in the list.
So when riding in Thailand, it your not going for a long way journey, I think it should be safe to pump gasohol - for a short period. But if you planning a ride more than 10 fills up. Do try to look for gasoline.
Basic guide on the Thailand pump station is :
REGULAR 95 is labeled in Yellow
REGULAR 91 labeled in Red
GASOHOL 95 label is Orange
GASOHOL 91 label in Green
Although this might not correct for all pumps, it is mostly true for most of them. Do try to fuel in Shell, Caltex or PTT which is mainly a reputable gas station. My tips is, if you're bike can accept Ron 90+ and above, go for the Regular 91. Check the sticker label on your bike's tank, or check your bike's manual. But I guess, I can't confirmed because I didn't really notice, the price for Regular 91 is much more expensive than gasohol 95. Wait... Yup it's true. I've just browse the Net. Reg 91 somewhere 29.54 Baht (RM 2.99) and E10 Gasohol 95 is 25.74 Baht (RM 2.61). Notice Regular 95 is 36.64 Baht (RM 3.72) and only available from Petronas, Caltex, Susco and PT.
Update daily source here.
While gasohol advantage is that it might produce less emission, studied about 2% less than gasoline, it is reported to give less power than gasoline and lower mileage. Gasohol is also not friendly to older fuel injection and carburetors, even a new fuel injection which is claim to resist gasohol, it is not design for it. This case are meant on a superbike. Carburetors are claim can be damage with use of gasohol either in short or long term use and not very friendly to the plastic parts of the carburetors.
In other countries, there are arguement of using gasohol. But the noticable argument is about the cost of gasohol compared to the gasoline and is the consumer likely to gain advantage in using gasohol which in some country priced gasohol at gasoline price tag.