Thoughts on switching to Midgrade fuel?
 

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.

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

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.

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

-BC

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.

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,

https://www.helmet-stickers.com/xcart...mbs/t_2761.gif

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.

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.

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

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.

motorcycle manufacturers have to factor in all types of people riding in all types of conditions. big people, small people, riding with a passenger, outside temperature changes,altitude, etc. If you are not riding hard, and no passenger, mainly commuting to work, I would try a lower octane fuel. If it pings, drop a gear, and let off the throttle,it's not rocket science.

Yeah, I'm not riding it hard, no passengers, and so far the bulk of my riding is under 45 MPH. I'll try midgrade the next 2 tanks and see how it goes.

I filled up last night with 89 octane midgrade. So far no problems.

Just as I expected. I just thought it's too irresponsible to advise anyone else to experiment with their vehicles. My own is another question... we don't have any lower grade gas than 95 RON (AFAIK it's similar to your 91) so no room to experiment here, but in May I tried how Teresa likes E85. Well, she hates it. With 50% ethanol she kept stalling and while I could get away with 30% for that single tank it felt so much worse (and the fuel consumption went up too) that I won't try it again without auxiliary electronics... which I won't install anytime soon either.

Oh, no! Yeah, E85 is garbage for a non-flex fuel vehicle. Period. I hate having to use the 'up to 10% ethanol' garbage for lawn equipment.

I wonder how something like a bottle of Lucas Octane Booster mixed in with 4 gal of E85 would do for drag racing, though?

Sorry, random thought. :D

I figure with me being pretty easy on the throttle, and I have the parade fan to keep the heads cool in traffic, I can probably get away with 87 octane, but I'll take it one step at a time.

Re: Thoughts on switching to Midgrade fuel?
 

I tried midgrade in my '05 Heritage, but she just drank it, although running okay. The other danger of course is heat. Running hotter in an aircooled motor plus bad mileage is a no brainer.

Re: Thoughts on switching to Midgrade fuel?
 

I don't seem to be getting worse mileage on midgrade. However, in extremely hot temperatures, or if I plan on riding it hard I do put premium in it. Lately with the really cold temps I have been sliding in an occasional tank of 87 in it.

Re: Thoughts on switching to Midgrade fuel?
 

Come on.... Is the 30 bucks a year your gonna save put your kids thru college. They put the octane requirement on the bike for a reason. Do not whine about a re-build if it detonates and you smash a piston. IMO use what they tell ya to use but it's your bike,do what you want

Re: Thoughts on switching to Midgrade fuel?
 

Japanese motorcycles use (R)esearch octane, and we here in the US use R+M/2 According to wilkipedia, 91 R is about the same as 87 R+M/2. I have an older Japanese bike , and have no issues at all with the 87 in a motorcycle that specifies 91 Research octane. But of course you have an Amercian bike, so is would seem that 92/3 is what they intend on running in it, with a little breathing room. Larger cylinders tend to need more octane, if everything else is equal. The 89 plus some 93 thing seems as tho it would be right on as far as octane goes...

harley's usually have higher compression to if i remember correctly which will cause it 'knock' when the fuel pre-ignites from not being the right octane level. this will cause damage and costly repairs. so i'd recommend using the OEM octane recommendations.

Long & old thread that has been bumped. Believe Jay2TheRescue has heard this before, & he probably doesn't need repeats now. But here goes.
People using 87 octane 10% ethanol blends AREN'T using 87 octane fuel. First, the ethanol is 114 octane. Second, the gasoline molecules remaining, must have an average octane rating of 84 to balance the ethanol. The octane of the mishmash blend of fuels is anything BUT 87 octane. No wonder 10% ethanol blends often don't work properly, with knocking &/or loss of 8%, 7% & 5% mpg. On top of what 10% ethanol blends ARE, 10% ethanol blenders have been taken to court, because of mistaken double blending(forming 20% ethanol blends) & possible purposeful blending to as much as 64% AND sold as 10% ethanol blend.

HOWEVER, true 87 octane gasoline(ethanol-free) E0, does have molecules averaging 87 octane(duh).....that's it. How 'bout dat!! 87 octane fuel actually burning in octane 87 gasoline engines. Who woulda thot!!!!

Yeah, I've been putting in premium E10 in it. Lately I've been buying it at Sam's Club and paying the going rate for 87 octane. I still have yet to find a station selling premium E0 within a reasonable riding distance. I saw a dealer on puregas.org's site in Maryland that's about an hour away that supposedly has it. If they're reasonably priced I may just go there in the car every few weeks and fill up some 5 gallon cans to use in the lawnmower and motorcycle.

Hi Jay......Unlike some states that have increased their E0 sources dramatically in the past 2 or 3 years, Virginia & Maryland are right under the noses of the EPA. Maryland has only added 10 stations in the past year & a half, while Virginia has added about 34, but still under 300. The cool zoomable map on pure-gas.org does show a few 87 octane E0 sources in northern Virginia. Those still aren't near you? Yes, I've had a discussions with some of the pure-gas.org people. They are happy to see E0 served in ANY OCTANE. But I've stated its time, NOT to take the EPA piecemeal strategies to squash E0 sources, one being to restrict 87 octane E0. While E0 sources in upper octanes increase, the great unleashing of ethanol-free gasoline really needs the availability of 87 octane E0 everywhere.

The closest E0 source is the Pure station in Berryville, VA, which is about 30 miles from home. The nearest E0 premium station appears to be to the west of Winchester, over an hour away. There is a E0 premium station about 30 mins from my parent's house, but since it is a chainsaw dealer, I think it will probably be very expensive.

The problem with VA and MD is that DC is an area regulated by the EPA. The EPA mandates E10 within a certain mileage radius of DC.

This
 

Smart boy. :thumb:

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.

I see you have 80 fills so far. How long has it taken to go 80 fills? At 4 gallons per fill you'd save 60 cents or a total of $48 so far. At a fairly typical Harley 40mpg that's 160 miles per fill or around 13k miles so the $48 is about a penny every 3 miles. I agree with saving money whenever possible but is it enough in this case for any possible risk? Disclaimer, all arithmetic done this early before any breakfast is subject to who knows what sort of insane errors. :D

you'll get less mpg on lower octane. higher octane better for your engine. its worth the extra few cents.

Yeah, I've been using premium E10 in it. Still looking for a good source for premium E0.

I've used 89 or even 87 on my BMW on several occasions, mostly in the rural areas where 91 was hard to come by. Didn't notice any appreciable difference in the bike's behavior.

I just thought of something today about octane enhancers and the different grades at the pump. We know that ethanol is an octane enhancing fuel additive. We know from the labels on the pumps that "all fuels may contain up to 10% ethanol." The key words being "up to," but it doesn't also say that 87 octane may contain more or less octane enhancers than 91-93.

It would make sense that the simplest way to modify Premium to have a higher octane would be to increase its ethanol percentage. And for Regular octane fuel, keep its ethanol percentage to a minimum.

So for instance, 91 octane may actually contain 10% ethanol and 87 octane might have something much lower, say an ethanol percentage of 4%. I've searched the Web, but cannot verify my hypothesis. The one that eludes to it, CarGuys, doesn't give a percentage for premium nor a comparison to the amount contained in regular. I'll keep looking from time to time. Seems like a needle in the haystack question at the moment.

early 70s, muscle car owner's would add "heet" gas line anti-freeze to no lead fuel. to boost octane.

My opinion is that you should not switch. Stay with the 91 mark for now and if your situation remains the same, you can think of switching to 89 octane fuel.