[Mojoe]

This quote is taken from:
http://www.shell.ca/code/motoring/en...es/octane.html

Good source to point newbies at for the answer

There is definately a difference between US and canadian gas. When I had my 72 Nova with a 327 engine with a 3/4 crane cam and a holley 650 carb, running regular gas from the states was out. It would knock like a biatch. It would run ok on Canadian regular with no knocking. This comes from first hand experience because I buy half my gas in the states and half in Canada...depending on where I am at the time of day that I need it. It has been like this for 25 years. So what I have gathered, yes, we do use the same grading system, but the gas we sell is of a higher octane value. I also know for a fact that I can get approx 100-120 kms more on a tank of regular from Canada than I can from the states. With the price of gas, it is like a religion for us border community dwellers to decide where is the best place to buy gas. We have to calculate the mpg we estimate getting from each side, as well as the cost per gallon/exchange rate at the time. I guess you could say we have broken it down to a science...lol.

It could be something totally aside from the ocane rating itself that is giving you the difference -- the actual formulation instead. While the AKI/RON/MON/PON/Road Octane Number is based on a theoretically pure mix of x amount of heptane mixed with y amount of octane, the reality is that gasoline providers mix far more compounds into their fuels. Thus, if what you are buying in Canada has a better basis than what you are buying in the USA, even with identical Road Octane Numbers (or PONs, etc), it might give you significantly better performance. The other issue is the averaging issue -- if what you were buying in the US had a RON of 95 and a MON of 87, to give a PON of 91, while what you were buying in Canada had a RON of 92 and a MON of 90 (still resulting in a PON of 91), the Canadian blend would be better under typical off-idle use.

Cheers
=-= The CyberPoet

You could be right. I know we have just had "winter gas" available to us in the last year. I can't remember if it was shell or esso....or who it is, but apparently it is supposed to give quicker starting in low temps and be less prone to condensation problems which is common in winter climates. I have seen this gas at the pumps, and the octane is the same. I just never tried it. We have another gas as well, called Ethonal or methoonal... or something like that. It is designed to act as a cleaning agent for the fuel system. I tried it on a regular basis for a bit, but my fuel system never had a problem, so I did not see any noticable difference to make it justifiable to pay the higher price.

[The CyberPoet]

You could be right. I know we have just had "winter gas" available to us in the last year. I can't remember if it was shell or esso....or who it is, but apparently it is supposed to give quicker starting in low temps and be less prone to condensation problems which is common in winter climates. I have seen this gas at the pumps, and the octane is the same. I just never tried it. We have another gas as well, called Ethonal or methoonal... or something like that. It is designed to act as a cleaning agent for the fuel system. I tried it on a regular basis for a bit, but my fuel system never had a problem, so I did not see any noticable difference to make it justifiable to pay the higher price.

"Winter" gas normally has MTBE, ETBE, or TANE in it (basically ethers), an oxygenator compound, as well as an increased amount of high votility compounds such as pentane and butane (aeromatic compounds that would tend to want to "boil" off rapidly in the type of weather we enjoy here in Florida, at least in a non-vapor-sealed tank). Both of these changes in formulation tend to give much cleaner burns, but also tend to drive gas mileage down for carburetor-based vehicles and those with unsealed fuel tanks (because of increased votility means higher amounts of evaporative loss).
Ethanol and Methanol are alcohol-gasoline blends, which have both advantages and disadvantages (but I believe more disadvantages for most people unless they burn through gas very quickly -- say in a couple of days). Like MTBE, ETBE, and TANE, the alcohol increases the fuels votility and again can greatly decrease fuel mileage in non-sealed fuel systems.

There's an interesting read on some of these issues and on gas station fires increasing as a result of these compounds here.

Cheers
=-= The CyberPoet

[Mojoe]

You could be right. I know we have just had "winter gas" available to us in the last year. I can't remember if it was shell or esso....or who it is, but apparently it is supposed to give quicker starting in low temps and be less prone to condensation problems which is common in winter climates. I have seen this gas at the pumps, and the octane is the same. I just never tried it. We have another gas as well, called Ethonal or methoonal... or something like that. It is designed to act as a cleaning agent for the fuel system. I tried it on a regular basis for a bit, but my fuel system never had a problem, so I did not see any noticable difference to make it justifiable to pay the higher price.

"Winter" gas normally has MTBE, ETBE, or TANE in it (basically ethers), an oxygenator compound, as well as an increased amount of high votility compounds such as pentane and butane (aeromatic compounds that would tend to want to "boil" off rapidly in the type of weather we enjoy here in Florida, at least in a non-vapor-sealed tank). Both of these changes in formulation tend to give much cleaner burns, but also tend to drive gas mileage down for carburetor-based vehicles and those with unsealed fuel tanks (because of increased votility means higher amounts of evaporative loss).
Ethanol and Methanol are alcohol-gasoline blends, which have both advantages and disadvantages (but I believe more disadvantages for most people unless they burn through gas very quickly -- say in a couple of days). Like MTBE, ETBE, and TANE, the alcohol increases the fuels votility and again can greatly decrease fuel mileage in non-sealed fuel systems.

There's an interesting read on some of these issues and on gas station fires increasing as a result of these compounds here.

Cheers
=-= The CyberPoet

well one thing I do know for sure is that I have a sealed system. I discovered the hard way that my car would not run with a faulty gas cap. It kept stalling out. I changed the pump and I changed the filter...still did it. It was my stupid gas cap.

[mystahagy]

To the octane question, I can't tell a difference between 87 or 93 in my '95 concerning performance. What I DO notice however is a difference in the long term. Over time after running 87 the bike doesn't start up as quickly and doesn't idle as well. I'd suppose it has to do with how clean the gas burns... after switching back to 93 those symptoms gradually faded away. Being rejetted and whatnot I'd suppose my bike would be more prone to this happening, perhaps if my mixture isn't perfect.

[Mojoe]

To the octane question, I can't tell a difference between 87 or 93 in my '95 concerning performance. What I DO notice however is a difference in the long term. Over time after running 87 the bike doesn't start up as quickly and doesn't idle as well. I'd suppose it has to do with how clean the gas burns... after switching back to 93 those symptoms gradually faded away. Being rejetted and whatnot I'd suppose my bike would be more prone to this happening, perhaps if my mixture isn't perfect.

back in 93 when I bought my kat, the budget was tight. New house, 2 cars and a truck, the boat, all the expenses......and I did ALOT of riding, so I put the regular gas with the main reason being it was cheaper. It allowed me to do more riding with the allowance the ol' lady gave me.
Then when the budget changed and I became single, I went to super....and thought I would see a difference. After a few months, went right back to regular. In the 12 years and 120k+ miles I put on that kat, only about 2-3 months it ran on super.

[zleviticus]

bio-diesel... ?

I give my fuel a grade of F+

I use 87 octane...

[The CyberPoet]

To the octane question, I can't tell a difference between 87 or 93 in my '95 concerning performance. What I DO notice however is a difference in the long term. Over time after running 87 the bike doesn't start up as quickly and doesn't idle as well. I'd suppose it has to do with how clean the gas burns... after switching back to 93 those symptoms gradually faded away. Being rejetted and whatnot I'd suppose my bike would be more prone to this happening, perhaps if my mixture isn't perfect.

It's probably the detergents that are often bundled in the "premium" grade fuels making the differences -- not the octane levels themselves. For example, Shell's V3 Max has like 10 times the detergent level in their high-octane that their low-grade does. This would make a difference in how readily the fuel gums up the carb passages...

Cheers
=-= The CyberPoet

[WildKat]

I friend of mine works in MI, works w/ gas, tankers, etc all day. Ive talked to him many times about his job, and one of the things Ive found interesting is that when you go to the gas pumps, the higher octanes are actually a mixture and the first gallon or so is what's left in the pump hoses from the last person, so it's not always 89 or 93 or 94 octane till after the first gallon or 2.

[The CyberPoet]

I friend of mine works in MI, works w/ gas, tankers, etc all day. Ive talked to him many times about his job, and one of the things Ive found interesting is that when you go to the gas pumps, the higher octanes are actually a mixture and the first gallon or so is what's left in the pump hoses from the last person, so it's not always 89 or 93 or 94 octane till after the first gallon or 2.

I ran into this problem just a couple weeks ago with the Audi... Our Audi sips high-octane and for the first time in eons, I pulled into a station that uses a single hose for all three fuels, took on about $5 in gas (I was low on cash & on gas, and forgot my wallet at home) and drove off. By the next day, the car was acting all strange and I was thinking about how expensive it would be to redo everything (O2 sensors, fuel/air filters, plugs, plug wires, air mass sensor, injector cleanings, etc). Fortunately I had run low again and went by my regular station (a 3-hoser operation), filled up and the issues all went away... The moral of the story: if your vehicle cares for the top-grade, hit a station with one-hose per grade.

Cheers
=-= The CyberPoet

[md86]

To the octane question, I can't tell a difference between 87 or 93 in my '95 concerning performance. What I DO notice however is a difference in the long term. Over time after running 87 the bike doesn't start up as quickly and doesn't idle as well. I'd suppose it has to do with how clean the gas burns... after switching back to 93 those symptoms gradually faded away. Being rejetted and whatnot I'd suppose my bike would be more prone to this happening, perhaps if my mixture isn't perfect.

Really ? I seem to get the opposite happen . I ran on 89 for the longest time , then switched to 93 . After a few weeks on 93 , the bike runs a little sluggish , and eventually a plug fouled (was FINE with the 89) . My carbs are NOT perfect , I know this , but I never had a problem until I started with the 93 ...

[Anonymous]

The Tiller likes the good stuff...

[yellowkat]

i put sunoco's ultra 94 and noticed smoother and a little bit faster acceleration...

[Bob]

always the best, and yes even in california where the prices are way to high for gas the bike needs the love