Kawasaki Vulcan Forum banner

1 - 20 of 49 Posts

·
Registered
Joined
·
529 Posts
Discussion Starter #1
Was reading some random posts and came across a claim by more than one member on here that 87 octane actually ran noticeably better in their bikes. Personally I have never ran anything other than 93 but with the gas light on today I filled up with 87. I was only a mile from work, but I have a 30 mile ride home tonight so I should have an idea of how it runs by then.

What say you? Do you have any performance mods and what fuel grade runs best for you?
 

·
Premium Member
Joined
·
287 Posts
I just switched over to 87 from 91. I am on my first full tank with 87. Haven't noticed a difference yet.
 

·
BOTM Winner, May 2015
Joined
·
740 Posts
87! was doing 93, and was informed by a knowledgeable gentleman, I don't need to. Every now and then I run non ethanol in it, I use the 90 non ethanol in boat.. but the boat doesn't get used as much!
 

·
Registered
Joined
·
643 Posts
I have tried all grades no noticeable difference. I now stick with 87, use ethanol free when I can get it . The ethanol issue is a subject of its own.
 

·
Registered
Joined
·
16 Posts
I just finished a tank of 93 octane----never again: lost 10 mpg with no noticeable increase of anything but cost... It's back to 87 for me. I was just curious to see how it ran with it...
 

·
BOTM Winner, May 2015
Joined
·
740 Posts
I have tried all grades no noticeable difference. I now stick with 87, use ethanol free when I can get it . The ethanol issue is a subject of its own.
Absolutely about the ethanol. if I know I will not be riding much I will try to have it in the bike, if riding going threw tanks of gas, I don't.. Fortunately for me, my Gas station right down the road has it.. I am also in a huge area full of boats too.
 

·
Registered
Joined
·
98 Posts
Tried 91 first as I saw "minimum anti-knock index of 90" on page 37 of the manual - only to realize later that was the RON rating. Used 87 with no change.

I've got a K&N filter and will debaffle the stock exhaust soon ... will stick with 87 unless I hear pinging at which point I'll try 89.
 

·
Registered
Joined
·
729 Posts
87 for me.Have tried 91-92 lost a few mpg. I avg. high 40's to low 50's
A few times I put in some 89, Higher alt. an high 90's temp.
1+ on the ethanol, good for a drop of 3-4 mpg.
 

·
Registered
Joined
·
529 Posts
Discussion Starter #11
Well I tried it for 30 miles on the way home. Seemed fine down low but I could tell a small power loss above 4500. Exhaust sounded funny also. Bike pulsed harder with every stroke it seemed like it had high blood pressure. Obviously not long enough to check fuel mileage, but I poured some octane boost in when I got home. I'm too worried with the aftermarket mods that 87 will cause spark knock. No way I could hear it with the exhaust and ear plugs.
 

·
Registered
Joined
·
729 Posts
Should not be an issue on FI unless you mod compression and or timing (spark/cam). possibly higher temps and long grades.
 

·
BOTM Winner, June 2015
Joined
·
842 Posts
I run purely 87 ethanol free gas in mine unless I'm somewhere that it's not available. I have the PowerCommander V, Kuryakyn Hypercharger and HK Sideburner exhaust. I get more "popping" with higher octanes.
 

·
Registered
Joined
·
7,620 Posts
I got popping with higher octanes. Though I use 93 on the Vaquero. These engines don't adjust and tune themselves the way car engines do, so they don't really take advantage of higher octanes. I'm not sure why I got popping and poorer fuel economy, as others had experienced. Maybe higher octane fuels resistance to detonation also causes it to ignite fractionally slower having an "ignition retard" effect. I know on my Focus, which (like most cars) has an anti-knock sensor and a host of other sensor, timing is advanced (both through spark and the variable valve timing) when higher octane fuel is used, picking up horsepower. It's not that higher octane fuel makes more power; it's that with higher octane fuel, the engine can time itself more aggressively and make more power without being damaged by detonation/pinging. Our bikes don't do that, so there really isn't much of an advantage of running higher octane fuels where it's not necessary.
 

·
Registered
Joined
·
1,080 Posts
If you get popping with a higher octane, you need a tuner or you use lower octane. Run what the bike needs. Higher octane burns slower. You don't hear it with stock pipes. As long as the engine doesn't knock you are fine. If the popping bothers you go lower octane or buy a tuner.


Sent from Motorcycle.com Free App
 

·
Registered
Joined
·
3,089 Posts
I just finished a tank of 93 octane----never again: lost 10 mpg with no noticeable increase of anything but cost... It's back to 87 for me. I was just curious to see how it ran with it...
Lost 10mpg?

Seems odd.

My guess is that most of that loss is because you were trying to determine if there was increased performance, not a result of the fuel itself.
 

·
Registered
Joined
·
16 Posts
Lost 10mpg?

Seems odd.

My guess is that most of that loss is because you were trying to determine if there was increased performance, not a result of the fuel itself.
Nope.....same riding style. going to/from work every day. Didn't crack the throttle; I'm not a speed guy...never have been. I was actually hoping for better mileage so I was shocked when the fuel gauge kept dropping so fast.
 

·
Lifetime Premium Bike Of The Fall Winner 2017
Joined
·
2,856 Posts
I have the old girl a tank of the rich stuff, she didn't care for it. She likes the cheap hard stuff.
 

·
BOTM Winner, June 2015
Joined
·
842 Posts
If you get popping with a higher octane, you need a tuner or you use lower octane. Run what the bike needs. Higher octane burns slower. You don't hear it with stock pipes. As long as the engine doesn't knock you are fine. If the popping bothers you go lower octane or buy a tuner.


Sent from Motorcycle.com Free App
I have a tuner. But it still pops more with 93 and rarely pops with 87 non ethanol. Mine may be unique in that aspect.
 

·
Registered
Joined
·
7,620 Posts
If the tuner can adjust ignition timing it would probably be able to eliminate popping with a dyno. Getting the A/F ratio correct along with advancing timing would both improve performance (taking advantage of higher octane fuel) and eliminate the popping. Assuming there is a tuner that includes ignition out there for the 900 (unsure).

But mine was stock in that regard. Never was much of a performance guy.
 
1 - 20 of 49 Posts
Top