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I read the USA manual included with my new Grom and it mentions that only 86 octane is needed (Pump Octane Number). That's what we use in the USA right? So I guess it's just silly cheap to keep fueled up.

Poor picture of USA manual octane number below:

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I have started using Fuelly to track my fuel economy and so far I have only put 93 non-ethanol in the Grom. I plan to run that for a few tanks to get a good baseline before switching to 87 octane and seeing if there is any difference.
 

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I figure with the difference between the price of 87 and 93 octane running anywhere from $0.20-.50, why go cheap? That's a cost savings of only 75 cents per tank at most, assuming the greatest price spread and filling up the tank from bone dry. Unless the good stuff will burn out fuel injectors or cause some other kind of damage, which I doubt, I hardly see pinching pennies that tightly. It'll be only the good stuff for me.
 

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The problem with using higher octane when you don't need to isn't just about cost -- its about power. Using 93 when you don't need to (or 91) -- it actually COSTS you power. If the thing was made to run 87 octane -- you'll get more power, better gas mileage by using it then you will with 91. Now, if you can take advantage of the higher octane somehow... on a car, we would increase the timing for example. Increased compression would be a way on the bike.

Anyway, unless you have something thats going to cause the motor to detonate on 87 octane -- I would not suggest going higher. It won't help by itself.
 

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Yes, El Chorizo, I would tend to agree. For what it's worth, I have a 2012 fuel injected Quad and I was informed more than once that using high octane fuel would only make it run hotter. No real advantage. My high performance CRF, though, drinks the best. And she loves it!
 

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Here in cali i would recomend using 91. We get shit here. I have been using chevron for my bikes for 12 years now. And now use it with my gas card now for my vehicles. 5 bucks to fill up my tank aint bad. But i have my fuel juggs filled so i have been using that for now
 

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We need some dyno numbers on this for the Grom specifically. Or maybe I'll go back down to the low octane on my next fill up and see if I can suddenly get over 60mph.
 

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Yes, El Chorizo, I would tend to agree. For what it's worth, I have a 2012 fuel injected Quad and I was informed more than once that using high octane fuel would only make it run hotter. No real advantage. My high performance CRF, though, drinks the best. And she loves it!
I thought using a higher octane fuel usually makes an engine run COOLER.
 

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I thought using a higher octane fuel usually makes an engine run COOLER.
Octane is just a measure of the temperature before combustion starts. Thats why on high performance engines you need higher octane otherwise they will detonate. You will get combustion before the combustion cycle and thats not good.

I would think that it shouldn't affect the temperature at all, just less "bang" on every combustion cycle...

I only know the basics though, that question is probably better answered by someone else.

HowStuffWorks "What does octane mean?"
 

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Octane is a fuels resistance to knock (pre-det). It won't create more power without a retune. It will also not lose power.

Sent from my SPH-L720 using HondaGrom.net mobile app
 

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The problem with using higher octane when you don't need to isn't just about cost -- its about power. Using 93 when you don't need to (or 91) -- it actually COSTS you power. If the thing was made to run 87 octane -- you'll get more power, better gas mileage by using it then you will with 91. Now, if you can take advantage of the higher octane somehow... on a car, we would increase the timing for example. Increased compression would be a way on the bike.

Anyway, unless you have something thats going to cause the motor to detonate on 87 octane -- I would not suggest going higher. It won't help by itself.
Yes what hisensausage says is exactly correct..
 

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Here's another thing to consider. Most of the "premium" gasoline out there gets it's octane boost by increasing the amount of ethanol in it. Ethanol/methanol absorbs water out of the air like a sponge. Add in the water this ethanol/gasoline mix is exposed to during the production and transportation process and by the time it gets to the consumer it's pretty watered down.

If I could get straight gasoline easily I'd NEVER put any fuel with ethanol in it.

My buddy, who used to own the Honda shop where I'm trying to buy my Grom, told me that if he set up a Ruckus or Metropolitan and let it sit for a week they'd have to clean the carb before they could get it to run for the customer so he'd leave them on the floor dry until they were sold. The F. I. system on the Grom will probably help overcome this problem since the petrol swill is forced into the engine rather than dribbled in via gravity and vacuum.

If your Grom will run on the lower octane fuel just fine use it.

Here's another thing to consider. I used to be sold on the "high octane" myth and ran it in my stock four stroke woods bikes. I could NEVER get a good dead-engine start and was usually left at the line. One time I forgot to buy race gas and ended up running low octane elcheapo gas from a station up the road from the place I was racing. When they dropped the flag the bike fired on the first kick and ran just fine all day long. The way it was explained to me the slower-burning high octane fuel was the reason the bike was so difficult to start. Since then I've always run the lowest octane fuel in my carbureted bikes I can run with knock.

All this being said BMW's call for premium gasoline and their ignition advance is retarded when lower octane fuel is introduced into the system, reducing it's power but still allowing it to be safely ridden without damage. I don't think the Grom's F. I. system is this sophisticated but since I'm a flat world kind of guy and have no experience with a bike with F. I. I can't say this for sure.
 

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I only run non ethanol. Plenty of places around me with it. Although I will probably run two tanks of ethanol through to see what the gas mileage and performance is.
Are you talking pure ethanol?

Ethanol enriched gasoline is bad... the government forces the pumps to run it but thats only for cleaner emissions. It runs leaner then regular gasoline.
 

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Premium gas here in Canada is the only gas that does not have any ethanol content. That's what I put in all of my toys before they are going to set for any length of time. Yamaha has released several tech bulletins regarding oxygenated fuels and how they can POSSIBLY cause issues in powersports equipment.

Running Higher octane fuel in something that doesn't need to run it only causes carbon buildup, anyway. There's no need to run supreme in a 10:1 compression engine.

Fun fact: My 1999 CBR600F4 stated right in the manual that it only requires 87 octane... so that's all I had ever run in it, unless I was at the track.
 

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I have high octane in mine right now. When I start it I have to rev up or it'll die (in 100 degree heat so it's not a cold cold start). Starting to think that's effecting my top speed as well.
 

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Food for thought:

Dealer fill up: unknown RON = 96mpg
My 1st fill up: 92 RON = 86mpg

Switched to 87 RON for comparison. Already 56mi and two fuel bars off of full.
 
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