Always run 93 or the highest I can find if traveling. If your manual states 91, then i would not go any lower unless in a bind.

 

FYI, there are fuel cells out there you can buy in camping supplies (or on the net) by a company called "MRO". The easiest one ta pack is their 1-liter unit. Ah carry 4 of 'em at all times, an' swap the gas out in 'em every 60 days or so. Great for emergency use - some of the areas we travel in kin git kinda thin on gas stations....

 

That's rarely an option when you are on the I-40 or I-10 running through Arizona to Texas.

Sodo the modern looking stations get a different (i.e. better)type of gas or something?

I haven't had a problem with any octane with any load at this point. If you are running a stock motor (meaning stock compression), using something lower than 91 isn't going to matter as much. When youruna high compression motor then it's significantly more important to use a high octane gas! If you run a lower octane gas (and you might have to one day, just because the only gas station in a 200 mile radius has 87!), and you notice pinging or it starts running sluggish, then it would be best to avoid!

I typically run 89, sometimes 91 (we don't have 93 anywhere that I've seen). No real reason why I switch, mainly depends on whether I'm paying attention (since I usually put 87-89 in my car). I haven't had pinging or any problems with any of my bikes (03 carbed Lowrider, 05 EFI Glide). Every bike is different though.

 

91 is the highest I can find here in ABQ. I always use it. Haven't had a problem, but I can't say that using this octane is the answer. Saw today at the dealer called 'Rocket fuel'. Anyone heard of it or used it? If not, does anyone use any octane boost at all? I know that in my truck I will put some in every three tanks or so. Figuring that it will keep the jets clear and free on blockage. Would this be the same for my harley? I have a carb on my bike, and I have noticed less mpg lately. Although I have only ran three tanks on it since it was down for the winter.

 

Premium fuel octane will vary depending on altitude. The owner's manual recommendation is a number based at sea level, most luxury import cars also carry the same number recommendation. Around here, the mid-grade translates to what the book calls for. Additives do make a huge difference, I find Mobil and Marathon 93 so far the best around here. BP is OK, Citgo is no-no. Trial and error with premiums seem to be the norm.

 

If your bike DOESN'T PING - Use what you want...
My '01 runs Great on 89 - But my '07 Needs 91 or better!!!

 

I always use 87 unless it hot outside 90+. Unless you have a ping issue you don't need premium. I work in the auto repair industry and the additives are not strong enough to justify the price. I have not had my 07 in 90 degree weather yet. The new bikes are suppose to have ion sensing knock control. Harley has to plan for the worst condition in the country

 

What Chiabate said is worthing readingagain. ELEVATION has a lot to do with what octane you can run. The lower the sea level elevation the higher octane you need. You will experience detonation knockingon 89 octanein Phoenix, Arizona (1500')where it will not cause a problem in Flagstaff, Arizona (7,300) on the same bike, but use 91 if at all possible.

Hogback

 

i use the 91 octane as stated in the manual, small price to pay to treat my bike right...ride safe

 

Yes, it is very important to use the higest octane to reduce detonation due to leaner epa settings on newer bikes. Some gripe saying ts too expensive but everywhere Ive bought gas premium is only 20 cents higher than the 87 octane in a 5 gallon tank that's only 1 dollar between the worst and the best.