Gasoline

[Aquaholictom]

I have 2 friends that swear that there M8 engines run better and cooler on regular gasoline, although HD says use premium. They say the ECM will compensate for the regular gasoline. Has anyone heard of this?

[rhino 2]

I have 2 friends that swear that there M8 engines run better and cooler on regular gasoline, although HD says use premium. They say the ECM will compensate for the regular gasoline. Has anyone heard of this?

I always use 93 even though Harley recommends 91.....Sure the EMC will to some extent compensate...IE; Detune the engines spark advance...But i'm willing to bet their reason is 87 is cheaper then 91/93...Octane...

[Jack Klarich]

The M8 engines have spark knock sensors to deal with the knock to pull spark and timing away from the engine. You can use a lower octane gas tho I would not make a habit of it. Instead I would run a NO alcohol gas for a better burn. Less alcohol = more complete burn

[MDO]

The MOCO designed the engine to run on at least 91 octane due to the compression ratio & the way it's tuned.

It's kind of silly, to me, to spend that much on a vehicle & then try to save $2.50 at each fill up.

[LadyonaMission]

That is like someone paying $450.00 for new boots, then buying tube socks at the Dollar Store to wear with them.

[GARYD]

I ran 87 octane in all my Harleys(Vettes too) for over 30 years and never had a fuel related problem...ever. Why give our enemies more money then we have too?

I have NEVER heard of any Harley engine being destroyed by using regular gas.

Now some are saying we have to use "Top Tier" gas. When will this nonsense stop?

It's almost as bad as the "which oil" to use.

It's you bike - run whatever makes you feel warm and fuzzy.

[GARYD]

That is like someone paying $450.00 for new boots, then buying tube socks at the Dollar Store to wear with them.

What's wrong with tube socks??? I've been wearing them for almost 70 years.

BTW - who the hells pays $450 for boots?

[Trampas]

The M8 engines have spark knock sensors to deal with the knock to pull spark and timing away from the engine. You can use a lower octane gas tho I would not make a habit of it. Instead I would run a NO alcohol gas for a better burn. Less alcohol = more complete burn

Trying to find a gas station that doesn't have alcohol in it is pretty slim around here, most have it, some don't. As far as the 91 octane and above is very slim also and the ones that do have it also have alcohol in it, my station that I went to all the time for 91 started using alcohol and I complained, they said if it doesn't sell well, they will drop the alcohol, must be selling ok since it has been 2 years. I have a few around here that has 91 and no alcohol so that is where I get it now. I know you can use alcohol in the bikes but I personally will not unless I really have to, so far I haven't run into it. I use to have to drive around 15 miles to a gas station that had no alcohol in their 91 octane, now I don't have to they built a gas station that has 91 and no alcohol and only 5 miles from me and that works out great, real real close to interstate since I don't care for the local streets here, highway and interstates are better but could be improved for sure.

All for now Trampas

[ctdair]

My 2 cents worth on knock sensing and engine operation. Once a "knock" is detected the timing is altered incrementally until "knock" no longer detected but then timing is incremented back until "knock" detected and cycle repeats again. To the best of my knowledge the timing does not stay at a fixed value once "knock" has disappeared, it constanly responds to any given variable it has been progammed to respond to. So if non premium gas does induce a "knock" the programming will compensate but I would prefer that it not have to constantly "hunt" for the optimum timing value.

[ctdair]

What's wrong with tube socks??? I've been wearing them for almost 70 years.

BTW - who the hells pays $450 for boots?

Once you've worn a good pair of White's boots with Archease. And a good pair of Smartwool socks. You'll never wear cheap shoes or socks again. So I spend $450 and more on boots. and $25 a pair for socks

https://whitesboots.com/foreman/safety/roughneck/

[TrainingWheels]

What's wrong with tube socks??? I've been wearing them for almost 70 years.

BTW - who the hells pays $450 for boots?

Maybe people who don't wear tube socks

[DK Custom Products]

I have 2 friends that swear that there M8 engines run better and cooler on regular gasoline, although HD says use premium. They say the ECM will compensate for the regular gasoline. Has anyone heard of this?

I know with the old (pre-M8) Ion sensing knock control, when I ran (because there was nothing else around) 87 octane, I would still get some pre-ignition knock. The Ion sensing can only do so much/retard the timing a certain amount.

I even tried ethanol free 87 octane, without good results.

I have not tried it on my 2019 TG that has a more advance knock control program.

For those looking for pure gas (no ethanol) take a look at this website, it may help you find some near you.

https://www.pure-gas.org/

Kevin

[Jack Klarich]

I know with the old (pre-M8) Ion sensing knock control, when I ran (because there was nothing else around) 87 octane, I would still get some pre-ignition knock. The Ion sensing can only do so much/retard the timing a certain amount.

I even tried ethanol free 87 octane, without good results.

I have not tried it on my 2019 TG that has a more advance knock control program.

For those looking for pure gas (no ethanol) take a look at this website, it may help you find some near you.

https://www.pure-gas.org/

Kevin

My M8 likes the NO alcohol gas It runs about 15* cooler per the power vision ET reading, it appears to make the same power, I have never had any lag in the throttle or spark knock that I can hear

[Jack Klarich]

The M8 is a higher compression higher pressure running engine that needs higher octane fuel. The knock sensors not only detect engine knock and detonation but help to keep the engine running cooler than Ion sensing engines like the Twin Cam, and the knock sensors can react faster than the Ion sensing system.

[Philip R]

The M8 engines have spark knock sensors to deal with the knock to pull spark and timing away from the engine. You can use a lower octane gas tho I would not make a habit of it. Instead I would run a NO alcohol gas for a better burn. Less alcohol = more complete burn

A few places in my area have alcohol free in premium gas. There's lots of boaters here that demand it.

[DK Custom Products]

My M8 likes the NO alcohol gas It runs about 15* cooler per the power vision ET reading, it appears to make the same power, I have never had any lag in the throttle or spark knock that I can hear

What is the octane of the alcohol free gas that your running?

Kevin

[rhino 2]

What is the octane of the alcohol free gas that your running?

Kevin

I don't know what it is in Florida where Jack is located ....But where i get it in PA [I only used it in Chainsaws/Mowers/String trimers and leaf blowers] Its 91 octane..

[Jack Klarich]

What is the octane of the alcohol free gas that your running?

Kevin

Shell 91 Octane

[Zammy]

Interesting Jack, at our Shell station, they carry 90 no ethanol which is what I've used for the last 5 years.

[Jack Klarich]

Interesting Jack, at our Shell station, they carry 90 no ethanol which is what I've used for the last 5 years.

We have a local chain Gate gas stations that have ethanol free also