Thoughts on switching to Midgrade fuel?

[Jay2TheRescue]

Harley recommends 91 octane fuel, but since I'm not running the bike hard (I'm very rarely using more than 25% throttle), and it is computer controlled fuel injection, what are everyone's thoughts on me switching to 89 octane fuel? Saving $0.15/gal would be nice.

[mikehallbackhoe]

try it, and listen for pinging. if it pings, go back to premium. I run regular in my valkyrie with no problems.

[Jay2TheRescue]

Thanks. Do you know if the computer controls on motorcycles work like they do on cars? I'm pretty sure a car would retard the timing, I'm not sure about the bike though.

[bobc455]

If there are knock detectors on motorcycles, I would think they would have to be a lot smaller than the automotive versions...

-BC

[i-DSi]

My Honda CBF has got a lot of sensors (throttle position, MAPsensor, coolanttemp, airtemp, lambdasensor, bank angle sensor, rpm...) but I've never seen a motorcycle with a knocksensor.
My opinion: don't change to lower octane rate as manufacturers recommandation. You'll see that on that hot day, with a hot engine you need some power (think about your safety) and your engine will not deliver as designed and there's a risk on engine damage.
I would only risk it with a knocksensor, but even then your engine might not perform as expected.

[JBW]

Originally Posted by mikehallbackhoe

try it, and listen for pinging. if it pings, go back to premium. I run regular in my valkyrie with no problems.

try checking the mpg. which ever octane gives best mpg is the best fuel for your bike. that what i did. 1000 mi. mpg compar-o per each octane 87,89,91-94 R+M/2. results were the higher the octane the better the mpg. with the highest octane giving the best average mpg.

[GasSavers_JoeBob]

How many gallon tank do you have? Maybe a five gallon tank? Typically there's a 20 cent/gallon difference between regular and premium. If you pushed the bike into the gas station,



you might save a buck. At 40 mpg, that would be a savings of $50 in 10k miles. Not much, when you think about it.

OTOH, you could try a tank and see what happens...it might work ok.

[Jay2TheRescue]

In my area there's generally a $0.30 - $0.45/gal difference between 87 and 93 octane. You are right though, it is only a 5 gallon tank, and I haven't let it get under 1/2 tank so far.

I think I can do a good compromise. Since 91 is recommended, and stations in my area carry 87, 89, and 93, and I've been filling up at around 1/2 tank if I alternate between 89 and 93 then I'll end up with 91 in the tank.

[GasSavers_JoeBob]

Here, the only station I've seen with 93 octane gets $6.99/gallon for it.

[Jay2TheRescue]

In this area the Premium is 93, and one brand has 95. I think its Exxon that's 95 octane. I never really looked at Premium before now.