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[bubtrauma]

Hi GUYZ,

Harley says to use mid grade fuel in my 2014 Limited. What are the ramifications on using 87 octane. I mainly use mid but sometimes can only fine 87.

Bub

[Para Bellum]

As you know, octane is how we measure the fuel's resistance to igniting too early--before the spark hits it--causing problems that range from knocking (aka pinging) to burning a hole in the piston to trying to make the engine run backward.  So real damage can occur.  BUT modern engine control systems (ECM) have knock sensors to detect the problem, and when it happens, the ECM takes steps to reduce it.  When it does, you usually are going to have less power available.

If you are in a situation where you need the power, such as passing uphill, and can't afford to roll off or have the engine deliver less power...

[CVO Couple]

91 or better (mid grade). I run premuim 93 or better all the time.

[gmeikle]

Here in Perth Western Australia myself and most of my riding mates ( sorry "buddies" ) use 98 Octane fuel

At the "servo" AKA "gas station" we can buy 91 / 95 / 98 octane

All Australian petrol sold in Australia for over 10 years now is unleaded

I'm wondering if the Octane rating system here in Australia is the same as the US ?

[grc]

Hi GUYZ,

Harley says to use mid grade fuel in my 2014 Limited. What are the ramifications on using 87 octane. I mainly use mid but sometimes can only fine 87.

Bub

What actual octane number does the manual recommend?  US bikes have recommended 91 octane for at least as long as Twin Cams have been around, and around my little part of the world 91 octane is considered the minimum rating for premium (we do have 93 as well).  Mid grade here is 89 octane (R+M/2 method).

If your bike is supposed to run 91 octane or higher, a drop to 87 will probably cause some level of detonation under certain riding conditions.  Minor amounts can be handled by the engine management system, which will sense the abnormal combustion and back off the timing until it stops (up to a point anyway).  This of course will adversely affect performance.  If you have your bike tuned, I'd suggest you do so while running the octane level you can most easily find where you ride.  If that's 87 octane, have the bike tuned for 87 octane. 

Jerry

[J-Carr]

Having tried "premium" fuel in my truck and car and noticed no improvement in performance and a .5 mpg improvement that didn't cover the price difference I wondered the same thing.  Until I rented a bike in Vegas where they only have 87 and 89.  Wow.  The lack of power, I'm supposing because of the ECM trying (and at times failing) to control the knock was very noticeable.  We hunted down a station that had 91 (outskirts of town, east side).  The bike then ran pretty similar to how I'm used to them running here in the Northeast where you can get at least 92 and most places 93.

To Sum up:

87 was crap.  Very noticeable.
89 was crap.  I'd describe it as the bike felt off.
91 was normal.  Felt the same to me as running 92 in Pennsylvania.

I don't know if the dealer would tune it for 87, as Jerry suggests, if it would then perform OK in that range.  I do not believe Vegas HD takes their head out of their can long enough to check these bikes as one of the times we rented out there I got second degree burns on my thighs from the heat coming off the engine on one trip up the strip.  When I suggested tuning it to them, they told me all Harley's are like that... Having ridden many brand new bikes at my dealer (I sometimes help them bring demos to events) I knew that this was not the case.  Hot yes.  Burn my thighs till they blister, not so much.  BTW, every time I've been to Vegas it's been in November and the temps were never above the 80s in daytime.  My trip in stop and go traffic where I got the burns (and knock) was in the 50s at night.

I'm guessing low octane fuel and thin air caused that.  I'm also guessing that it could be tuned to adjust for that, or no one in Vegas would buy one.

[tdkkart]

 This is one of the reasons I keep the Power Vision tuner permanently attached to the bike.
Once I have a good 91 octane tune(91 is as high as I can consistently get here), I pick a good hot day, fill
up with 87 octane and go for a ride. I do a couple data logs making sure to record where the engine pings.
I then go back and tweak the tune till I get rid of the ping and save it as an 87 octane tune. When I get
to a spot that only has 87, which has happened, it takes 30 seconds to load the 87 octane tune while I'm
standing at the pump.
 

[J-Carr]

Wow... And people call me anal retentive OCD. 

I say that not to be insulting but with admiration for your dedication to a purpose.  I know there's no way in hell I'd take the time or effort to switch tunes when I had to switch Octane.  I think I'd just buy a bottle of Octane boost and bump it up.  But more power to you for the effort. 

[tdkkart]

Wow... And people call me anal retentive OCD. 
I say that not to be insulting but with admiration for your dedication to a purpose.  I know there's no way in hell I'd take the time or effort to switch tunes when I had to switch Octane.  I think I'd just buy a bottle of Octane boost and bump it up.  But more power to you for the effort. 

 Heh, I like tinkerin' with chit, and I've got the tuner so why not use it to it's potential??
I the time that it takes you to go inside and buy a bottle of booster I can either load my custom tune, or simply adjust the mid-range timing on the tune I have.

[J-Carr]

Touche! 

I guess its good I live where they have 93 octane.  No worries for me.

Beside my tuner is a SERT.  Getting out the laptop and booting it into Windows would give me enough time to refine my own 93 octane. 

[bubtrauma]

Thanx for the input guyz

[rayz1951]

93 octane all the time, if not available I use an octane booster.

[Para Bellum]

Getting out the laptop and booting it into Windows would give me enough time to refine my own 93 octane. 

Good one.

[covgrt]

It is tuned to use the higher octane your truck is not

Sent from my SM-G920V using Tapatalk

[Chief2505]

I generally use 91 or 93 which ever is available. One time though I was in Missouri hills and the only thing I found was 89 non ethanol. I put it in and I swear the bike ran better than on the 91 or 93 ethanol based gasoline!

I have used 87 at times in a pinch and generally will get 91 or 93 within 100 miles or so to sort of blend it out.

I do not really notice a difference in performance because I generally do not hot rod the bike all the time.