What do you do???

[Okie Triker]

First time I've ever run into this - out cruising today through some of the smaller off-the-beaten-path smaller towns and stopped for a drink and to top off the fuel, but there was a sign on the pump that said "mid-grade and premium grades out". No sweat, still had over a quarter of a tank so went to the next stop about 15 miles down the road, and darned if it didn't say the same thing. Like I said, I still had enough to get me back to civilization this time, but what would you do if you had to have gas and all they had available is regular unleaded?

[Sloufoot]

First time I've ever run into this - out cruising today through some of the smaller off-the-beaten-path smaller towns and stopped for a drink and to top off the fuel, but there was a sign on the pump that said "mid-grade and premium grades out". No sweat, still had over a quarter of a tank so went to the next stop about 15 miles down the road, and darned if it didn't say the same thing. Like I said, I still had enough to get me back to civilization this time, but what would you do if you had to have gas and all they had available is regular unleaded?

That is the reason you carry a bottle of octane boost in the trunk !

[Gorilla]

really push come to shove. fill up with enough to get you by. Don't put more load then necessary. and continue on.

[Scalp Hunter]

Ride a gw, it doesn't care what grade you put in it.pepper

[donjack]

A tank of regular every now and then in a emergency type incident isn't going to hurt anything, only if you run regular grade all the time. A small bottle of octane booster in the trunk will also take care of this type problem. Have fun, enjoy your new ride.

[Sloufoot]

Ride a gw, it doesn't care what grade you put in it.pepper

Is that because they don't have enough compression to ping ???

[msocko3]

Is that because they don't have enough compression to ping ???

Actually the GL1800 engine has more compression than the 103" Twin Cam, 1800 compression is 9.8:1 vs the 103 @ 9.6:1. If Honda wanted they could bump the compression up to 10.1 without a problem, they can get away with it due to the liquid cooling. Harley requires 91 octane due to the air cooled engine which has has combustion chamber temps that run a lot hotter than a liquid cooled engine.

As to the dilemma the OP had, I'd just carry some octane booster or put enough of the lower grade fuel to get me to a station that has what I needed. I run into this problem some years ago with my 06 Ultra which had a 95" build running 10.1 compression and 195 CCP. I painted myself into a corner and had to pump 87 octane in, I put 2 gallons in and located a station down the road that had premium, I ended up down shifting a lot while I had just the 87 octane, it pinged like crazy if I didn't.

[Rick Kay]

I ran into this same situation in Canada, a few years ago, except that is was another 100 miles for the next fuel. I put in 3 gallons, and took it very easy until I could get better fuel. My motor was an Evo with 10:1 pistons. No problem with pinging, but I would only run regular fuel in an emergency.

[Phu Cat]

Harley requires 91 octane due to the air cooled engine which has has combustion chamber temps that run a lot hotter than a liquid cooled engine.



Don't think that's the case, Socko. Air cooled engine designers have to allow for enough cooling or our air cooled bikes would ping all the time. And, once again, 91 octane does nor run cooler, faster, hotter, or slower than 87 octane. It is only less likely to ping under certain conditions. Nor does extra octane provide any more power, altho many people suggest otherwise. You can trust what I'm telling you as I made gasoline for almost 15 years when there was a refinery in Cincinnati.(God I loved that job.)

I'm thinking HD says to use premium due to its having much more detergent than regular to keep the injectors clean

Phu Cat

[scooty]

I have ran all of my bikes on different grades of fuel when the 91+ is not available and they ran fine. Let's see NO gas or REGULAR gas HMMMMMMMM I think I'll go with the regular gas ! ! ! !

[msocko3]

Harley requires 91 octane due to the air cooled engine which has has combustion chamber temps that run a lot hotter than a liquid cooled engine.


Don't think that's the case, Socko. Air cooled engine designers have to allow for enough cooling or our air cooled bikes would ping all the time. And, once again, 91 octane does nor run cooler, faster, hotter, or slower than 87 octane. It is only less likely to ping under certain conditions. Nor does extra octane provide any more power, altho many people suggest otherwise. You can trust what I'm telling you as I made gasoline for almost 15 years when there was a refinery in Cincinnati.(God I loved that job.)


I'm thinking HD says to use premium due to its having much more detergent than regular to keep the injectors clean


Phu Cat

Let me know how 87 octane works out for you on a 95 degree day riding loaded 2 up and pulling a nice grade at 65 mph in 6th gear on a 2011 and later Triglide which is equivalent to 5th gear on my 06 Ultra, bet it pings. Harley is specifying 91 octane because as you know it will support the 9.6:1 compression and a hotter combustion chamber which the air cooled engine is living with. I sure didn't say it made the engine run cooler, I'm smarter than that, I also know extra octane doesn't add power. I spent many of years building engines for muscle cars and drag cars with compressions from 10.1 to 13.1, I spent a good deal of time studying fuel.

Some years back when I had my 05 Electraglide Classic and the 88" engine at Stage 1 with mufflers I could run 87 octane in the spring. Once the outside temps hit 80 the only fuel choice for that bike was 91, with 87 it would kick back on the starter and ping when 2 up. I don't think the better detergent package in the 91 was keeping it from kicking back and pinging in the warmer weather.

[rhino 2]

I use high test 91/93 with all my Toys, Chain saws also, Does it give me better performance, Who knows, Makes me feel better and when i feel better my Machines feel better.
That said, If i pulled into a gas station and all they had was 87 , I'll use it, been there done that and never had a problem, I usually stop at gas stations because i need gas, not because i like to talk to the attendants, So pulling out and looking for another station is not for me.

[Bikerbozo]

I have to do that every once in a while. I would swear to a little loss of power, but otherwise no real problem. I've been trying to only use gas pumps that have seperate hoses also, since I think I am getting too many gal of last gas pumped.

[scooty]

Here is something that I have often thought about : most gas stations probably sell 95 % regular grade gas which means that the higher octane gas probably sits in the ground for quite a while before the tank needs to be refilled ::: here's my question, will this 91 octane gas degrade over time and lose some of it's punch ? ? ? so could you possibly be better off with fresh 87 octane or old 91 ? ? ?

[Sloufoot]

Actually the GL1800 engine has more compression than the 103" Twin Cam, 1800 compression is 9.8:1 vs the 103 @ 9.6:1. If Honda wanted they could bump the compression up to 10.1 without a problem, they can get away with it due to the liquid cooling. Harley requires 91 octane due to the air cooled engine which has has combustion chamber temps that run a lot hotter than a liquid cooled engine.

Yeah I know that Mike.... just tryin to rib Honda drivers a little.... Sounds like I found more than one.... No harm inferred ! But good information for everyone tho.
I also own an older Wing. Not the same engine, but ain't no cherry either......

Ride Safe !

[Bigbill]

I had to use a tank of 87 octane last summer (piss poor planing on my part). Truth be told I really didn't notice a lot of difference. Seemed a little sluggish. Maybe a perception problem. Soon as I got down to a half tank I filled with 91 octane. IMHO I believe in a pinch 87 will do no harm.

[Sloufoot]

Harley requires 91 octane due to the air cooled engine which has has combustion chamber temps that run a lot hotter than a liquid cooled engine.


Don't think that's the case, Socko. Air cooled engine designers have to allow for enough cooling or our air cooled bikes would ping all the time. And, once again, 91 octane does nor run cooler, faster, hotter, or slower than 87 octane. It is only less likely to ping under certain conditions. Nor does extra octane provide any more power, altho many people suggest otherwise. You can trust what I'm telling you as I made gasoline for almost 15 years when there was a refinery in Cincinnati.I'm thinking HD says to use premium due to its having much more detergent than regular to keep the injectors clean
(God I loved that job.)Phu Cat

You know it would take a book length reply to explain how octane rating is obtained in gasoline, and how they make it. Also at least as long to explain how it is used to perform correctly in different engines.
That being said, 85-87 octane burns faster than 91-93 octane. Given an engine at X# compression, and X* advance in the timing, if the engine was designed to run 91+ at these settings, the 87 gasoline will ignite & burn too soon. Before the piston reaches TDC. Then as the piston further compresses the combustion chamber you get the ping as it over pressures the combustion chamber. Causing excess heat, and like taking a hammer to the top of the piston !
The higher octane fuel lets you advance the spark, and up the compression thus producing more power. The fuel doesn't completely ignite before TDC of the piston & finishes burning in the down stroke of the piston.
Higher compression produces higher combustion chamber temps just by it's self. That is why a diesel engine can run without a spark plug. It does it all with compression. Diesel has a cetane rating that works like gas' octane rating.
That is an over simplification of the process, but....................
Aircraft air cooled engines use 100 to 140 octane. I think the 140 is the upper end , not sure, might be a little higher.
So,,,,, what ever you want to do to your bike, have at it and run that low grade stuff.....!
By the way as said before on here, use a pump with a separate hose for the premium fuel. It takes over 2 gallons to flush out the gas left in the hose & pump.

Have a nice day & Ride Safe !

[msocko3]

Yeah I know that Mike.... just tryin to rib Honda drivers a little.... Sounds like I found more than one.... No harm inferred ! But good information for everyone tho.
I also own an older Wing. Not the same engine, but ain't no cherry either......

Ride Safe !

No offense taken, I figured you was looking for a bit of a rise which I was more than happy to provide.

[rap47]

Having two brothers that worked for two differant gas stations for the last thirty five years or so, I was told by them that the posted octane ratings are the minimum for that pump. They say a posted 87 octane could be higher than 87, just not lower.

[Lakeman]

I carry a one gallon can (plastic) with me in the trunk. It is treated with marine sta-bil. I find it hard to believe two gallons in the pump, if that were the case I would be paying for hi-test and pumping regular. Don't see this being allowed. If so that sux!