The Gasohol A Go-go

[Maejo Man]

With the advent of gasohol95 and gasohol91 the only real alternative seems to be regular 91 which has a far lower octane rating than the outlawed 95, and has also risen to an incredible 27.50 a litre.

What long term effects will the use of gasohol fuel have on modern car engines, and have the government done their homework? What do you use and why, and what are your views on the new fuel?

[Mid]

the only real alternative

diesel

[Maejo Man]

the only real alternative

diesel

I suppose if I asked what beer you prefered now that you can't get Carlsberg, you'd probably answer Vodka

[nidge]

Vodka is good, a much better replacement to Carlsberg. Plus i believe its CFC free, ozone friendly and low in polyunsaturated fats.

[mcgriffith]

Have a Honda motorsai (2007 CBR 150) which has an 11:1 compression ratio. For you non-motorheads, this is higher by far than any car motor out there, unless you own a fully tuned exotic.

My bike runs fine on 91.

One of the biggest mis-understandings on the part of motorists is that a higher octane rating, say 95 vs. 91, provides more power.

It is the exact opposite. Use the LOWEST octane rated fuel (in a NATURALLY ASPIRATED ENGINE; turbo/supercharged whole different deal) in your motor that does not cause detonation (pre-ignition, also caused "knocking").

My advice? Go with the 91 (non-gasohol) for any high-perf motor. You got an older Beemer? 91. Old Range Rover w/ V-8? 91.

I think you'll find it runs just fine.

BTW, 91 octane fuel in America is the "premium" grade. Most cars sold today there are engineered and tuned to run on 89 octane.

McG

[Maejo Man]

Vodka is good, a much better replacement to Carlsberg. Plus i believe its CFC free, ozone friendly and low in polyunsaturated fats.

I really should have known better than to post a serious thread here, knowing all you get is arsedbrained rhetoric

[nidge]

Have a Honda motorsai (2007 CBR 150) which has an 11:1 compression ratio. For you non-motorheads, this is higher by far than any car motor out there, unless you own a fully tuned exotic.

My bike runs fine on 91.

One of the biggest mis-understandings on the part of motorists is that a higher octane rating, say 95 vs. 91, provides more power.

It is the exact opposite. Use the LOWEST octane rated fuel (in a NATURALLY ASPIRATED ENGINE; turbo/supercharged whole different deal) in your motor that does not cause detonation (pre-ignition, also caused "knocking").

My advice? Go with the 91 (non-gasohol) for any high-perf motor. You got an older Beemer? 91. Old Range Rover w/ V-8? 91.

I think you'll find it runs just fine.

BTW, 91 octane fuel in America is the "premium" grade. Most cars sold today there are engineered and tuned to run on 89 octane.

McG

I didn't understand half of that! But what i did understand was very helpful. thank you for some factual information at last

[Tywais]

I'm still able to get 95 (nonalcohol) at the Jet on the road to Hang Dong, so doesn't seem to be 'outlawed' yet. BTW, my Bluebird has a 2 liter turbo charged engine, thus I don't want to run it on 91.

[Maejo Man]

Have a Honda motorsai (2007 CBR 150) which has an 11:1 compression ratio. For you non-motorheads, this is higher by far than any car motor out there, unless you own a fully tuned exotic.

My bike runs fine on 91.

One of the biggest mis-understandings on the part of motorists is that a higher octane rating, say 95 vs. 91, provides more power.

It is the exact opposite. Use the LOWEST octane rated fuel (in a NATURALLY ASPIRATED ENGINE; turbo/supercharged whole different deal) in your motor that does not cause detonation (pre-ignition, also caused "knocking").

Some sound obsevations there Macca. My Cooper "S" has a compression ratio of 10.8:1 which is close to your Honda, and will only perform well with high octane, aspirated through a 45DC0E side draught Webber.

That aside, I tried 95 gasohol the other day in my Honda (4 wheels) and was amazed at the lack of performance, it was like driving a plate of rice pudding. Luckily I only put in a few hundred baht's worth. I then topped up with 91 with a noticed improvement. So that has to be the way to go....

[mcgriffith]

I'm still able to get 95 (nonalcohol) at the Jet on the road to Hang Dong, so doesn't seem to be 'outlawed' yet. BTW, my Bluebird has a 2 liter turbo charged engine, thus I don't want to run it on 91.

And you are absolutely right, you should run the highest octane fuel available in a turbo.

If and when you can't find 95 (non-gasohol) you will seriously have to look at changing the mapping on the ECU, and/or turning down the boost on your turbo....

McG

[Maejo Man]

I'm still able to get 95 (nonalcohol) at the Jet on the road to Hang Dong, so doesn't seem to be 'outlawed' yet. BTW, my Bluebird has a 2 liter turbo charged engine, thus I don't want to run it on 91.

Unfortunately the last of the reserves I fear but I migh have to tank up on it for a flying trip to Payao next week Thanks for the tip

[Mid]

here's your answer .

[Maejo Man]

here's your answer .

Not really

What do you use and why, and what are your views on the new fuel? was what I asked, but thanks for the link, I had seen your post on it before.

[chanchao]

> What do you use and why,

Bio-diesel.

Cheaper, better, cleaner.

[higgy88]

As an old hippy motorhead, and a mechanical engineer who spent 15 years (1976 to 1991) designing engines for Chrysler, I definately have my very strong opinions on this subject. I also have quite a bit of knowledge, but only for Chrysler vehicles. And I can get very long winded and very boring, so please bear with me. First, I want to say that Chrysler began making all of their vehicles E10 (10% ethanol) compatable in 1986. That was 21 years ago. It is my very strong opinion that any vehicle manufacturer who has not also done so in the last 20 years has done a very great disservice to their customers (with the possible exception of the vehicle in post #2). I have also lived through the mid seventies when leaded fuel was replaced with unleaded fuel, and I can assure you that neither the gov't nor anyone else gave a <deleted> that all my vehicles at that time absolutely had to have leaded fuel. I can again see the handwriting on the wall my friends, and I do believe that it is a very good possibility that gasohol will be completely replacing pure petrol, so you'd better start preparing yourselves. What do I use on my vehicles? My wife has a 4 year old Toyota Vios and I have a 5 year old Honda Phantom 200cc, and I use 91 octane unleaded fuel for both those vechiles. Why? Because the owner's manual tells me to. Just a note to Mr. Mcgriffith. There are two ways to measure octane, the research octane number (RON) and the motored octane number (MON). What you get here in Thailand is just the research number, which is always higher. In the US, the number on the pump is the average of the two (R+M/2) so you really can't compare the two. The US also has three grades of fuel (87,89,and 91 called regular, super regular, and premium) while Thailand only has the two (91 and 95 called benzene and super). I can also tell you of the improvements made to the air/fuel intake system and design of the compustion chamber that allows for higher compression ratios while still being able to use the lower octane fuels. The engines in the 60s are very different than the engines nowadays. And a note to Mr. Twyais. Chrysler had two versions of it's 2.2 L engine, which I was intimately familiar with, a naturally aspirated version and a turbocharged version. The NA engine had a compression ratio of 8.9:1 and ran perfectly well on regular fuel. On the turbo version, we had to reduce the compression ratio to 8.1:1 and it absolutely had to use premium or you were going to blow holes in the top of the pistons. Now for the second part of the question. Would I use gasohol in my vehicles?. Absolutely not, unless I am forced to do so. Why? Simple answer, water contamination. Water seeping into the underground fuel storage tanks at the gas stations is a problem all over the world, and I can see this being an even bigger problem in Thailand especially now during the rainy season. Fortunately, water does not mix with pure gasoline, and the water sinks to the bottom of the storage tank because it is heavier. Unfortunately, the ethanol in the gasohol likes water and attracts it. And engines definately do not run very well with even small amounts of water in the fuel. It is my opinion, Mr. Maejo Man, that is why your vehicle ran so poorly, not because of the gasohol itself. You will see a small deterioration in performance with gasohol but not that much. I'd be willing to bet the farm (a good bet since I don't have one) that if you go back and fill up with gasohol in the middle of the hot season when it hasn't rained for a good couple of months and everything is completely dried out, then you won't have much problems at all.

[Maejo Man]

As an old hippy motorhead.....................................Would I use gasohol in my vehicles?. Absolutely not, unless I am forced to do so. Why? Simple answer, water contamination. Water seeping into the underground fuel storage tanks at the gas stations is a problem all over the world, and I can see this being an even bigger problem in Thailand especially now during the rainy season. Fortunately, water does not mix with pure gasoline, and the water sinks to the bottom of the storage tank because it is heavier. Unfortunately, the ethanol in the gasohol likes water and attracts it. And engines definately do not run very well with even small amounts of water in the fuel. It is my opinion, Mr. Maejo Man, that is why your vehicle ran so poorly, not because of the gasohol itself. You will see a small deterioration in performance with gasohol but not that much. I'd be willing to bet the farm (a good bet since I don't have one) that if you go back and fill up with gasohol in the middle of the hot season when it hasn't rained for a good couple of months and everything is completely dried out, then you won't have much problems at all.

An excellent post Higgy88 and yes I should have realised that alcohol/methanol fractionations have an affinity for water, and will do untold damage if used continually. Thanks for the effort on the post..MM

[PeaceBlondie]

Hey, I actually understand some of that engineering stuff, and now I know that gasohol is hydroscopic. Or hygroscopic, attracting water.

In Chiang Mai, can we discuss which brands of service station still seem to have 95 octane no-gasohol? I usually find it at Shell, PTP, and Jet. I notice that the Shell station just beyond Central on Huay Kaew is now open all night long. There are very few stations in the inner city, but quite a few once you get outside the moat.

Lately I buy 95 no-gasohol at 30.74 baht per liter, even though our CBR150 owners' manuals have a big red 91 sticker on the front cover. Does my bike run better on 95 than 91? Not that it's noticeable. I think I've found the right 95 octane fuel when I see the current price is over 30 baht, at least 30.69.

I speak no more Thai at service stations than "sawadee khrap, gow-ha, dem tank." Which translated from Swahili may mean "Howdy y'all, 95, fill tank." But when will we know that the 95 octane fuel has alcohol? How do you say in perfect northern or central dialect, "Ola, Jose, does this fuel contain alcohol?"

[tigerbeer]

my car manual says 91. but i stick to 95. why? cause its only a few satangs cheaper than 95. so might as well go with 95.

my question is though, especially to higgy88. why does the thai government not realise about this water contamination thing? why do they insist on going gasohol?

btw, PB, i fill up at the ESSO petrol station after carrefour on the way going to lampang. before makro. they have 95 petrol.

[higgy88]

PB, I really can't understand why you are using 95 when the owner's manual says you can use 91. You're spending more money but your engine (and you) cannot tell the difference at all. All the octane number tells you is the fuel's resistance to pre-ignition, the higher the number the greater resistance to pre-igniton and if it isn't going to pre-ignite at 91 octane then it is also not going to pre-ignite at 95 octane. The higher octane fuel does not do anything else.

[higgy88]

Very good question TB, and I can assure you I have absolutely no idea why the Thai gov't does or does not do anything. I'm just trying to use the best fuel for my vehicles same as everyone else over here.

[mcgriffith]

As an old hippy motorhead, and a mechanical engineer who spent 15 years (1976 to 1991) designing engines for Chrysler, I definately have my very strong opinions on this subject. I also have quite a bit of knowledge, but only for Chrysler vehicles. And I can get very long winded and very boring, so please bear with me. First, I want to say that Chrysler began making all of their vehicles E10 (10% ethanol) compatable in 1986. That was 21 years ago. It is my very strong opinion that any vehicle manufacturer who has not also done so in the last 20 years has done a very great disservice to their customers (with the possible exception of the vehicle in post #2). I have also lived through the mid seventies when leaded fuel was replaced with unleaded fuel, and I can assure you that neither the gov't nor anyone else gave a <deleted> that all my vehicles at that time absolutely had to have leaded fuel. I can again see the handwriting on the wall my friends, and I do believe that it is a very good possibility that gasohol will be completely replacing pure petrol, so you'd better start preparing yourselves. What do I use on my vehicles? My wife has a 4 year old Toyota Vios and I have a 5 year old Honda Phantom 200cc, and I use 91 octane unleaded fuel for both those vechiles. Why? Because the owner's manual tells me to. Just a note to Mr. Mcgriffith. There are two ways to measure octane, the research octane number (RON) and the motored octane number (MON). What you get here in Thailand is just the research number, which is always higher. In the US, the number on the pump is the average of the two (R+M/2) so you really can't compare the two. The US also has three grades of fuel (87,89,and 91 called regular, super regular, and premium) while Thailand only has the two (91 and 95 called benzene and super). I can also tell you of the improvements made to the air/fuel intake system and design of the compustion chamber that allows for higher compression ratios while still being able to use the lower octane fuels. The engines in the 60s are very different than the engines nowadays. And a note to Mr. Twyais. Chrysler had two versions of it's 2.2 L engine, which I was intimately familiar with, a naturally aspirated version and a turbocharged version. The NA engine had a compression ratio of 8.9:1 and ran perfectly well on regular fuel. On the turbo version, we had to reduce the compression ratio to 8.1:1 and it absolutely had to use premium or you were going to blow holes in the top of the pistons. Now for the second part of the question. Would I use gasohol in my vehicles?. Absolutely not, unless I am forced to do so. Why? Simple answer, water contamination. Water seeping into the underground fuel storage tanks at the gas stations is a problem all over the world, and I can see this being an even bigger problem in Thailand especially now during the rainy season. Fortunately, water does not mix with pure gasoline, and the water sinks to the bottom of the storage tank because it is heavier. Unfortunately, the ethanol in the gasohol likes water and attracts it. And engines definately do not run very well with even small amounts of water in the fuel. It is my opinion, Mr. Maejo Man, that is why your vehicle ran so poorly, not because of the gasohol itself. You will see a small deterioration in performance with gasohol but not that much. I'd be willing to bet the farm (a good bet since I don't have one) that if you go back and fill up with gasohol in the middle of the hot season when it hasn't rained for a good couple of months and everything is completely dried out, then you won't have much problems at all.

higgy, you are right on. Didn't mention RON vs. MON averaging in US at pump as I didn't want to have everyone's eyes glaze over from boredom . As a sidenote, I will mention that I DO use very high octane fuel occasionally- in my GSX-R 1000 racebike. VP and Nutec produce highly oxygenated fuels that produce more power than pump gas, but have a very controlled flame speed. Best of both worlds. Of course, a 5 gallon can costs about $90 USD.....

McG

[PeaceBlondie]

Okay, higgie, you've got me convinced that I'm wasting about 90 satang per liter. I don't ride a third as much as I did in my first two years, when I averaged 1,600 km per month, always on regular 91 octane.

So, are there also two kinds of pump petrol for 91 octane, as well? How do I know which is witch hazel?

[lotus eater]

As an old hippy motorhead, and a mechanical engineer who spent 15 years (1976 to 1991) designing engines for Chrysler, I definately have my very strong opinions on this subject. I also have quite a bit of knowledge, but only for Chrysler vehicles. And I can get very long winded and very boring, so please bear with me. First, I want to say that Chrysler began making all of their vehicles E10 (10% ethanol) compatable in 1986. That was 21 years ago. It is my very strong opinion that any vehicle manufacturer who has not also done so in the last 20 years has done a very great disservice to their customers (with the possible exception of the vehicle in post #2). I have also lived through the mid seventies when leaded fuel was replaced with unleaded fuel, and I can assure you that neither the gov't nor anyone else gave a <deleted> that all my vehicles at that time absolutely had to have leaded fuel. I can again see the handwriting on the wall my friends, and I do believe that it is a very good possibility that gasohol will be completely replacing pure petrol, so you'd better start preparing yourselves. What do I use on my vehicles? My wife has a 4 year old Toyota Vios and I have a 5 year old Honda Phantom 200cc, and I use 91 octane unleaded fuel for both those vechiles. Why? Because the owner's manual tells me to. Just a note to Mr. Mcgriffith. There are two ways to measure octane, the research octane number (RON) and the motored octane number (MON). What you get here in Thailand is just the research number, which is always higher. In the US, the number on the pump is the average of the two (R+M/2) so you really can't compare the two. The US also has three grades of fuel (87,89,and 91 called regular, super regular, and premium) while Thailand only has the two (91 and 95 called benzene and super). I can also tell you of the improvements made to the air/fuel intake system and design of the compustion chamber that allows for higher compression ratios while still being able to use the lower octane fuels. The engines in the 60s are very different than the engines nowadays. And a note to Mr. Twyais. Chrysler had two versions of it's 2.2 L engine, which I was intimately familiar with, a naturally aspirated version and a turbocharged version. The NA engine had a compression ratio of 8.9:1 and ran perfectly well on regular fuel. On the turbo version, we had to reduce the compression ratio to 8.1:1 and it absolutely had to use premium or you were going to blow holes in the top of the pistons. Now for the second part of the question. Would I use gasohol in my vehicles?. Absolutely not, unless I am forced to do so. Why? Simple answer, water contamination. Water seeping into the underground fuel storage tanks at the gas stations is a problem all over the world, and I can see this being an even bigger problem in Thailand especially now during the rainy season. Fortunately, water does not mix with pure gasoline, and the water sinks to the bottom of the storage tank because it is heavier. Unfortunately, the ethanol in the gasohol likes water and attracts it. And engines definately do not run very well with even small amounts of water in the fuel. It is my opinion, Mr. Maejo Man, that is why your vehicle ran so poorly, not because of the gasohol itself. You will see a small deterioration in performance with gasohol but not that much. I'd be willing to bet the farm (a good bet since I don't have one) that if you go back and fill up with gasohol in the middle of the hot season when it hasn't rained for a good couple of months and everything is completely dried out, then you won't have much problems at all.

I've really tried to follow this and - for much of it, though not all - succeeded, I think. But may I cut to the chase and ask the really simple and selfish question - what should I choose between gazohol and 91 petrol for my 2 litre, one year old, assembled in the Philippines, Mazda3 automatic? (I've been using gazohol most of the time.)

[higgy88]

Lotus Eater, here's the current specs for your car from the Mazda Thailand site. Mazda Thailand I think we can safely assume that last year's model isn't different, as well as being assembled in the Philipines. They are very clear that you need to use 95 and that you can use gasohol. Definately do not use 91 as it would be the same as playing russian roulette with your car. Don't get me wrong about gasohol. Not all stations are going to have problems with water contamination. If you have found a good one and your car is running good on gasohol, just keep going there. You will know immediately if there is any water in the fuel. A good idea for you guys, like Twyais, who have to use 95 is to test out a particular station. When you are getting pretty low on fuel, put in maybe 100 or 200 baht worth and drive around. Do this a few times and if you don't have any problems then you should be pretty safe and just continue to go to the same place if you can. Now, with all of the rain, is a very good time to do this and test out the stations where you would most likely fill up.

A note to McG. Unlike you, I have absoluely no problem being boring as it is one of the few things I do very well. And I will always have the satisfaction of knowing that I have helped many of my obviously deprived engineering students at CMU getting some much need sleep.

[lotus eater]

higgy88, thank you for helping me out with a clear answer. Will not use 91 - haven't so far. The only thing I have noticed about 95 petrol is that it gave me distinctly better mileage and power than gasohol; but if 95 petrol is being phased out, that's that.

So far I've not found it practical to adopt a particular station. But my car will be more settled - in my soon to be home town, Chiang Rai - and there I'll try to find and stick with one. (I don't suppose my chances with one brand station is better than another - ie if one had a better policy of insisting on better quality installation from their franchisees than another brand. Maybe that was a silly question.)

[BlissfullyIgnorant]

Lots of good info has been posted, but here's a couple of additional facts I haven't seen mentioned:

1. The octane requirement of an engine decreases with altitude. While research results on the subject differ, the concensus is that for Chiangmai's base altitude (310m) the octane requirement is reduced between 1.5 RON and 2.5 RON. Add to that the level of safety margin your vehicle manufacturer would have included in their design, and the tight control any recent cars electronics maintain over the stoichiometric ratio and timing, and it's difficult to foresee any issues running a 95 RON rated engine on 91 RON in CNX.

2. Ethanol has a lower calorific value than benzene, so any form of "gasohol" will have less total energy stored than its corresponding non-blended variant.

Edited July 8, 2007 by BlissfullyIgnorant

[PeaceBlondie]

So, how do we order 91 octane gasoline/benzene without gasohol? Gow-sip-et mai mee gasohol? In what tones of northern Thai?

[BlissfullyIgnorant]

Gow-sip-et, mai ow gasohon krup

[PeaceBlondie]

Gow-sip-et, mai ow gasohon krup

Of course, gasohon. At the Shen station right after Centran.

[mcgriffith]

My favolit station, Shenn....