Touring Models Road King, Road King Custom, Road King Classic, Road Glide, Street Glide, Electra Glide, Electra Glide Classic, and Electra Glide Ultra Classic bikes.
Sponsored by:
Sponsored by:

89 octane ethanol free or 91 with ethanol?

Thread Tools
 
Search this Thread
 
Old Jul 12, 2014 | 05:30 PM
  #1  
road king Q's Avatar
road king Q
Thread Starter
|
Road Master
10 Year Member
Liked
Loved
Community Favorite
Joined: Apr 2014
Posts: 927
Likes: 256
From: North Arkansas
Default 89 octane ethanol free or 91 with ethanol?

I did not read all the gas posts... sorry. Did not see this specific scenario, tho

My local stations, I live very rural, have only the options listed in the title. I can get 89 pure gas at one station... he only carries 87 and 89. 91 at another station... which accepts credit cards. Just curious which would be my best option. I usually factor in how soon I know I will ride again. A day or two, I get the alcohol gas.

On my ride today I got 91 pure gas in another town. Just getting enough runs to compare mileage on the two options. I would rather no ethanol, but my book says 91 octane..... so
 
Reply
Old Jul 12, 2014 | 05:37 PM
  #2  
Ragtop's Avatar
Ragtop
Ultimate HDF Member
15 Year Member
Liked
Loved
Community Favorite
Joined: Sep 2006
Posts: 7,101
Likes: 1,013
Default

I would go with the pure gas, wish I could get it around here.
Especially for that last fill up of the year before storage.
 
Reply
Old Jul 12, 2014 | 06:22 PM
  #3  
ddm502001's Avatar
ddm502001
Road Warrior
Joined: Dec 2008
Posts: 1,616
Likes: 17
From: Mid West
Default

I generally won't use less than 92 in mine. Have had to make due with corn gas in KS but worked at finding straight gas as often as possible, I would stick to the higher 91.
 
Reply
Old Jul 12, 2014 | 06:31 PM
  #4  
OldBill's Avatar
OldBill
Intermediate
Joined: Aug 2013
Posts: 26
Likes: 0
From: Mesa, AZ
Default

Take a look at this website. I use it all the time.

http://pure-gas.org/index.jsp?stateprov=AR
 
Reply
Old Jul 12, 2014 | 07:31 PM
  #5  
DresserDude's Avatar
DresserDude
Road Warrior
Joined: Mar 2011
Posts: 1,747
Likes: 47
From: Central Florida
Default

Do you want "6" of something or a half dozen instead?
 
Reply
Old Jul 12, 2014 | 07:43 PM
  #6  
RollaMo's Avatar
RollaMo
Grand HDF Member
15 Year Member
Liked
Community Favorite
Top Answer: 1
Joined: May 2008
Posts: 4,585
Likes: 673
From: Rolla
Default

Originally Posted by road king Q
I did not read all the gas posts... sorry. Did not see this specific scenario, tho

My local stations, I live very rural, have only the options listed in the title. I can get 89 pure gas at one station... he only carries 87 and 89. 91 at another station... which accepts credit cards. Just curious which would be my best option. I usually factor in how soon I know I will ride again. A day or two, I get the alcohol gas.

On my ride today I got 91 pure gas in another town. Just getting enough runs to compare mileage on the two options. I would rather no ethanol, but my book says 91 octane..... so
The higher octane of the 91 is more important than the lack of Ethanol in the 87 grade.
10% Ethanol is not going to hurt your bike at all.
I would use 91 or higher all the time, Ethanol or not.
 
Reply
Old Jul 12, 2014 | 07:51 PM
  #7  
Hausguy's Avatar
Hausguy
Road Master
Joined: Mar 2013
Posts: 1,151
Likes: 14
From: Seattle
Default

Why don't you run a tank of each and see which your bike prefers. On a road trip last year I got "stuck" using 89 pure and it was the best running fuel of the entire trip.
 
Reply
Old Jul 12, 2014 | 07:54 PM
  #8  
btsom's Avatar
btsom
Grand HDF Member
10 Year Member
Community Builder
Liked
Top Answer: 1
Joined: Jan 2012
Posts: 4,459
Likes: 2,896
From: Oklahoma
Default

Octane rating indicates resistance to spontaneous combustion without help from the spark plug. Compression creates heat, that is how a diesel engine works. The amount of heat generated depends on compression ratio and the amount of air getting into the cylinder. Because no conditions are given in the manual, you can assume that 91 octane is good at sea level. The higher above sea level you go, the less air there is. The less air there is, the less heat is generated by compression and the less octane is needed to prevent knocking/ping/pre-ignition. Experimenting with 89 octane won't hurt anything, at least for a short time. If you run your machine down fairly low on fuel, you can put in a couple of gallons of 89 and try it. If you don't get any ping, 89 will work for you at that altitude. If you do get ping, top off with 91 and that should minimize the pinging until you again re-fill with more 91. I live in the Oklahoma City metro area and 100% gas is still available here. The elevation here is about 1300 feet above sea level and I have been using 89 octane for several years and it performs very well with no ping.
 
Reply
HD Forum Stories

The Best of Harley-Davidson for Lifelong Riders

story-0

6 Weirdest Harley-Davidsons Ever Sold to the Public

 Verdad Gallardo
story-1

7 Times Harley-Davidson Chucked Tradition Out the Window

 Verdad Gallardo
story-2

7 Surprising Harley-Davidson Products that Are Not Motorcycles

 Verdad Gallardo
story-3

8 Best Harley-Davidson Motorcycles Ever

 Pouria Savadkouei
story-4

10 Worst Harley-Davidson Motorcycles Ever

 Pouria Savadkouei
story-5

Killer Custom's Jail Break Is The Breakout That Refused to Blend In

 Verdad Gallardo
story-6

Crazy Bunderbike Build Looks Amazing, But Is It Impossible to Ride?

 Verdad Gallardo
story-7

Harley-Davidson Reveals Super Cool Cafe Racer Concept

 Verdad Gallardo
story-8

Engraved Rebellion: Inside Bundnerbike's Glam Rock II

 Verdad Gallardo
story-9

10 Motorcycles You Should Never Buy

 Joe Kucinski
Old Jul 12, 2014 | 08:07 PM
  #9  
jpalm's Avatar
jpalm
Road Master
15 Year Member
Liked
Joined: Aug 2010
Posts: 755
Likes: 57
From: St. Augustine, FL
Default

Originally Posted by RollaMo
The higher octane of the 91 is more important than the lack of Ethanol in the 87 grade.
10% Ethanol is not going to hurt your bike at all.
I would use 91 or higher all the time, Ethanol or not.
I work for the local PD here and we've had a lot of problems with our vehicles. One of the techs at the city garage told me that a rep from GM came out to meet with them, and they have been doing the same with many other large cities around the country. As part of their investigation into the problems they've been collecting fuel samples from the vehicles. He said they've never found 10% ethanol in the vehicles. The lowest they have found is 11% and the highest was 31%, with the average being 19%. He claims that is part of the problem with the sensors on the new flex-fuel vehicles. The ethanol content is so high in the fuel that the vehicle sensors think it is E85 with low ethanol content, thereby setting off the fuel system warnings. I just picked up some Startron and I'm going to start running it in the tank. Rather be safe than sorry.
 
Reply
Old Jul 12, 2014 | 09:17 PM
  #10  
road king Q's Avatar
road king Q
Thread Starter
|
Road Master
10 Year Member
Liked
Loved
Community Favorite
Joined: Apr 2014
Posts: 927
Likes: 256
From: North Arkansas
Default

Originally Posted by Hausguy
Why don't you run a tank of each and see which your bike prefers. .
I have been alternating. I usually tank up a bit under a half tank. Have been told keeping it full leads to less condensation/water in tank. So I guess I have been running a mix. I would gladly use the 91 pure if i could get it.

I have noticed no running issues and minimal if any mpg diff

Sometimes know when I can get out again, sometimes not. May be a week tops between rides. Rarely more than that without at least a 40ish mile lake run
 
Reply



All times are GMT -5. The time now is 12:12 AM.

story-0
6 Weirdest Harley-Davidsons Ever Sold to the Public

Slideshow: From military-inspired singles to scooters and three-wheel utility vehicles, these Harleys took the company far outside its comfort zone.

By Verdad Gallardo | 2026-06-02 18:34:10


VIEW MORE
story-1
7 Times Harley-Davidson Chucked Tradition Out the Window

Slideshow: Harley-Davidson built its reputation on nostalgia, but every so often, the company took a hard left turn into the future.

By Verdad Gallardo | 2026-05-20 11:18:19


VIEW MORE
story-2
7 Surprising Harley-Davidson Products that Are Not Motorcycles

Slideshow: The bar-and-shield logo shows up on far more than motorcycles, some of the company's most unexpected products have nothing to do with riding.

By Verdad Gallardo | 2026-04-29 16:50:35


VIEW MORE
story-3
8 Best Harley-Davidson Motorcycles Ever

Slideshow: Not every Harley gets it right, but these are the ones that genuinely earned their reputation.

By Pouria Savadkouei | 2026-04-15 14:23:21


VIEW MORE
story-4
10 Worst Harley-Davidson Motorcycles Ever

Slideshow: From the troubled AMF years to modern misfires, these bikes earned reputations for reliability issues, questionable engineering, or disappointing performance.

By Pouria Savadkouei | 2026-04-01 20:01:09


VIEW MORE
story-5
Killer Custom's Jail Break Is The Breakout That Refused to Blend In

Slideshow: Killer Custom's "Jail Breaker" build focuses more on stance and visual aggression than mechanical overhaul.

By Verdad Gallardo | 2026-03-18 19:20:32


VIEW MORE
story-6
Crazy Bunderbike Build Looks Amazing, But Is It Impossible to Ride?

Slideshow: The Swiss custom shop has taken a Harley Softail and stretched it into something so long and low that it looks closer to a rolling sculpture than a conventional motorcycle.

By Verdad Gallardo | 2026-03-07 16:15:30


VIEW MORE
story-7
Harley-Davidson Reveals Super Cool Cafe Racer Concept

Slideshow: Harley-Davidson's new RMCR concept revives the café racer formula with modern hardware-and it may be exactly the reset the company needs.

By Verdad Gallardo | 2026-03-04 12:23:37


VIEW MORE
story-8
Engraved Rebellion: Inside Bundnerbike's Glam Rock II

Slideshow: A standard cruiser becomes an intricate metal canvas in the hands of a Swiss custom house known for pushing Harley-Davidson platforms far beyond their factory brief.

By Verdad Gallardo | 2026-02-24 18:19:44


VIEW MORE
story-9
10 Motorcycles You Should Never Buy

Slideshow: There is no shortage of great motorcycles to buy, but we would avoid these ten.

By Joe Kucinski | 2026-02-19 14:50:51


VIEW MORE