Ethanol-free fuels

Onagoth said:
does everyone here actually use 91 in their bikes?

I guess that’s a side question but it’s pretty expensive these days
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Current bike demands it per the service manual. Previous bike demanded 87, but previous owner always pumped 91, so I continued with it. I know it was overkill.
 
PrivatePilot said:
and your engine doesn't require high octane, IMHO you're wasting your money - same goes for your car.
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I mostly agree, but it is a little more complicated than this with some modern cars. Some cars only require 87 but to achieve the hp numbers quoted they need 91. They basically pull timing when run on 87 which cuts 5% or more of the horsepower. I am sure if bikes aren't there yet, they will be soon. I actually like this approach as most of the time I am not interested in the extra fuel cost just to have a bit more power available for the occasional full throttle run. I just wish manufacturers would be straight up and actually publish power numbers with the minimum required fuel as well as premium fuel.
 
It sounds like i I’ll be ok with 87, but I checked the manual is it says use 91

I’ve always used 91 in my snowblower and lawnmower with much better results.

I guess it wouldn’t be too expensive given how much I ride. Just kind of ******** that we can’t buy ethanol free fuels at lower octanes
 
Onagoth said:
does everyone here actually use 91 in their bikes?

I guess that’s a side question but it’s pretty expensive these days
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My bike manual states to run 91. But I was talking with someone and they mentioned not all grades are what they say they are. Meh who knows. I am currently testing out 87 on a couple of tanks to see if it makes any difference.
 
sburns said:
My bike manual states to run 91. But I was talking with someone and they mentioned not all grades are what they say they are. Meh who knows. I am currently testing out 87 on a couple of tanks to see if it makes any difference.
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Manufacturers have to provide a safe fuel spec for any situation. Climbing a mountain in a hot climate is much more likely to trigger detonation than cruising the 401. You may find that 87 works for you most of the time.
 
GreyGhost said:
Manufacturers have to provide a safe fuel spec for any situation. Climbing a mountain in a hot climate is much more likely to trigger detonation than cruising the 401. You may find that 87 works for you most of the time.
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Huh whatch u talking about Willis?? ?
If your bike explodes in any circumstance that would seem very strange.
 
sburns said:
Huh whatch u talking about Willis?? ?
If your bike explodes in any circumstance that would seem very strange.
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detonation GG is referring to is premature ignition
lower octane fuels in high compression engines can set off early
results in the expansion force downward while the piston is still in upstroke
over time this will break things

usually only happens when you start to play with engines - turbos and stuff

my turbocharged Subie has a detonation sensor that changes the fuel map
if you put regular gas in it, to prevent detonation, runs like a POS like that
 
The detonation that does the worst damage you won't hear like you can hear "pinging".
 
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Carbed bike. Run regular for decades, used to store it with same too. Only started using Shell 91 and stabiliser the last few years as the last tank of the season. Actually ran out of gas across the street from the station last year going to fill up. Hibernation used to be short, but last few have been longer, so maybe the 91 helped. Otherwise haven't really noticed and difference in spring start up. Mower and blower get regular.
 
Track bike, genny, mower and slowblower get ethanol free, everything else - street bike and cars - get regular.


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GreyGhost said:
I mostly agree, but it is a little more complicated than this with some modern cars. Some cars only require 87 but to achieve the hp numbers quoted they need 91. They basically pull timing when run on 87 which cuts 5% or more of the horsepower.
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If the car states 87 is "acceptable if no other option" (more or less) but "91 is recommended", chances are it actually does require high octane and as someone touched on a few replies above, the ECM is just programmed to detect detonation (that's why modern cars have knock sensors) and retard the timing to compensate.

Yes, this will trash performance, but so long as the manual specifies low octane is acceptable, it won't hurt anything in the long term.

That said, if the manual mentions nothing about low octane use then the engine is designed for high octane - not using it can potentially lead to damage if used for extended periods, or under high performance situations. You will probably get away with using it for gentle daily driving however, but there's no guarantee either - detonation damage isn't exactly visible, and many don't know the symptoms.

I used to own a Grand Prix GTP (the one with the supercharger) and it specified 91. I had to run 87 in it once (was in the north and there was no other option for a tank full) and the performance difference was staggering - the ECM retarded the timing so far that it went from a ballsy car to a real slug.

For a motorcycle that states it requires 91, I wouldn't skimp either - non electronic bikes will have no idea they're detonating, and even more modern electronic bikes may not have a knock sensor and/or be able to retard timing sufficiently to avoid damage long term.

However, most will agree, running high octane in a vehicle that only requires low octane (and mentions nothing about anything higher) is a waste of money - it's just marketing that makes people think it's somehow beneficial, to the benefit of the oil companies bank accounts, that's it.
 
JavaFan said:
detonation GG is referring to is premature ignition
lower octane fuels in high compression engines can set off early
results in the expansion force downward while the piston is still in upstroke
over time this will break things

usually only happens when you start to play with engines - turbos and stuff

my turbocharged Subie has a detonation sensor that changes the fuel map
if you put regular gas in it, to prevent detonation, runs like a POS like that
Click to expand...
I just hang around here because it's fun, but you guys really know your stuff, so now I need to learn stuff here too :ROFLMAO::ROFLMAO:

Thanks @JavaFan and @GreyGhost
 
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Ethanol can especially wreak havoc in older machines (motorcycles, snowmobiles, boats, etc.) with plastic fuel tanks and hoses not resistant to the damage it can create when something is stored for long periods of time. Using a fuel stabilizer and draining the carb(s) can only do so much.
Hence why its a good idea, if you have something that is used infrequently, to find ethanol-free.
 
I wonder about potential damages done by Ethanol in the fuel. It's a PIA to look for Shell gas stations just to avoid Ethanol. Is there any mechanics that have seen damages done by Ethanol when not being stored?
 
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