My V11 seemed to run perfectly on 87 Octanes (Regular) gas rating... strange?

[p6x]

I came back yesterday from a 1050 miles errand in the sizzling Texas current weather. Max temperature while riding 115 deg F as read on my Formotion temperature gauge before it sheared (again) from its support.

I had to refuel at a Halon station somewhere between Abilene and Coleman; only two choices "Diesel" or "Regular" (87 Octanes) fuel.

Now, on the swing arm of my V11, there is an adhesive that states that I should not run with fuel below 91 Octanes, meaning "Premium". By the way, Halon seem to be the main provider of gas in rural Texas. Their "Premium" is 90 Octanes.

I have had the experience to run engines on low octanes back when I was living in Europe. So I knew what to expect even if modern engines are more resilient to run with lower octane fuel.

The Guzzi did not gave out a single of expected symptoms. In fact, I could distinguish no evidence of having changed fuel quality. The engine responded in exactly the same way.

Anyone else ran with regular gas unscathed?

I did not take it for granted though, and I refilled with Premium to up the Octanes at every opportunity.

[docc]

I have had the same experience, yet choose to run premium. Since Shell introduced its V-Power Nitro+, I try to run that exclusively. My Sport certainly approves!

Travel sometimes demands alternatives, yet mySport tolerates this as long as I have not neglected any aspect of her state of tune.

[LaGrasta]

Whoops, I never new it was intended to run Premium, only ever ran Regular. Next fill-up, I'll give Premium a try, and see if I notice.

[GuzziMoto]

I would think of it as better to have the additional margin of safety you would get running premium. Since if it is an issue, you would not necessarily know it until it was too late and the damage is done. I would rather have extra safety margin. But to be fair, the V11 mill is fairly low compression and likely could run just fine on regular. But in certain situations it could become an issue. But true detonation is hard to hear, and the damage it can cause is serious. To me it is not worth taking the chance. I burn so little gas relatively speaking in my bikes that paying a little more per gallon is no big deal to me.

Also, the octane requirements are greatly affected by air density. Lower air density means lower octane requirements for the same engine.

[p6x]

4 hours ago, GuzziMoto said:

I would think of it as better to have the additional margin of safety you would get running premium. Since if it is an issue, you would not necessarily know it until it was too late and the damage is done. I would rather have extra safety margin. But to be fair, the V11 mill is fairly low compression and likely could run just fine on regular. But in certain situations it could become an issue. But true detonation is hard to hear, and the damage it can cause is serious. To me it is not worth taking the chance. I burn so little gas relatively speaking in my bikes that paying a little more per gallon is no big deal to me.

Also, the octane requirements are greatly affected by air density. Lower air density means lower octane requirements for the same engine.

True, it used to be easier to find out when you did not refill your tank with the required octanes.

One of the telltale way was to open the throttle with the engine at lower revs than usual for that specific gear. Then you would get the knocking which would be easy to hear on a motorcycle with the heads close to you. But it is not a open/shut case any longer. The ECU maps are designed to adapt according to what fuel is being burned. Maybe also our V11?

In my case, I did not feel any difference to engine behavior.

The second way was auto-ignition. But this was back in the carburetors day. You would switch off the ignition, and the engine would keep running as long as the fuel supply last from the carbs. With modern engines, when you switch off, the fuel injection is too.

 

 

[p6x]

5 hours ago, docc said:

I have had the same experience, yet choose to run premium. Since Shell introduced its V-Power Nitro+, I try to run that exclusively. My Sport certainly approves!

Travel sometimes demands alternatives, yet mySport tolerates this as long as I have not neglected any aspect of her state of tune.

My idle is very low. 600 rpm. 87, 90, 91 or 93 octanes, never stalled, even if it feels that it will. I know that I am below the minimum recommended by Guzzi.

[docc]

25 minutes ago, p6x said:

My idle is very low. 600 rpm. 87, 90, 91 or 93 octanes, never stalled, even if it feels that it will. I know that I am below the minimum recommended by Guzzi.

My goodness, yes! Have you verified your tachometer error with an ECU interface like GuzziDiag? The tach may also be reading optimistically.

Higher idle speeds have several important advantages for our V11, including lubrication, cooling, and reduced wear on the clutch mechanism.

[Lucky Phil]

7 hours ago, p6x said:

I came back yesterday from a 1050 miles errand in the sizzling Texas current weather. Max temperature while riding 115 deg F as read on my Formotion temperature gauge before it sheared (again) from its support.

I had to refuel at a Halon station somewhere between Abilene and Coleman; only two choices "Diesel" or "Regular" (87 Octanes) fuel.

Now, on the swing arm of my V11, there is an adhesive that states that I should not run with fuel below 91 Octanes, meaning "Premium". By the way, Halon seem to be the main provider of gas in rural Texas. Their "Premium" is 90 Octanes.

I have had the experience to run engines on low octanes back when I was living in Europe. So I knew what to expect even if modern engines are more resilient to run with lower octane fuel.

The Guzzi did not gave out a single of expected symptoms. In fact, I could distinguish no evidence of having changed fuel quality. The engine responded in exactly the same way.

Anyone else ran with regular gas unscathed?

I did not take it for granted though, and I refilled with Premium to up the Octanes at every opportunity.

Apart from all the marketing garbage there is one reason only to run an engine on high or higher octane fuel, detonation. If the engine doesn't have a detonation problem or the running environment or riding style precludes detonation events then high octane fuels are actually a slight disadvantage. Lower volatility of high octane fuels means harder starting, worse carburation in colder weather, poorer low throttle response, less intake air temp reduction due to latent heat of evaporation etc. If it doesn't need higher octane fuel then there is a tangible disadvantage in running it besides the additional costs. Maybe your bike is running richer than ideal and you were riding it at low loads and even in the hot weather you had enough detonation head room that it was ok. Of course maybe your hearing is suspect and you can't hear detonation and ping. 

Interestingly during the war the Germans had all sorts of issues with their high octane fuels causing engine bearing failures due to fuel dilution. To get the octane rating up and due to critical shortages they were using low volatility aromatics that didn't evaporate off effectively so the oil diluted permanently and cause bearing failures. 

I do know back in the mid 80's with the first injected 851 Ducatis that were raced tuners ran what they were used to using IE 100 octane avgas and they ran worse than on pump gas and I met a production bike racer at the TT back in 86 that ran it in his Kawasaki 600 at the TT in the production class and he said it carburated worse on the 100 octane.

 

Phil

 

 

[MartyNZ]

In different parts of the world, octane is measured differently. In NZ the octane reported at the pump is the RON value only. In the US, octane is calculated as (RON + MON)/2. 100 octane in NZ would be somewhere around 95 octane in the US.

 I wonder what the Moto Guzzi V11 fuel recommendation refers to? RON or (RON + MON)/2?

I tried 100 RON and as @Lucky Phil said, it made no difference, so was wasted money. However, Avgas is different.

When I was a young apprentice, I "salvaged" a 25litre drum of 100/130 (green Avgas) from a DC3 going into maintenance and put it in my Honda CB450.

It felt faster, so I tested it. It reached 1000rpm more in top gear at the bend on Harewood Road on 100/130 than the "96 Super" of the time. I previously thought that higher octane was only worthwhile with higher compression or a blower, but there it was going faster.

Obviously there was some other difference than just octane rating for this fuel to give noticably more power. I had just fitted new 1st oversize pistons and rings, and XS650 cans, but otherwise the 450 was standard.

I know that Avgas has less volatiles to avoid boil-off and vapor lock at altitude, and I assume higher calorific value ingredients which made such a noticeable difference.

[docc]

38 minutes ago, MartyNZ said:

I know that Avgas has less volatiles to avoid boil-off and vapor lock at altitude, and I assume higher calorific value ingredients which made such a noticeable difference.

I dated a girl in college that had higher calorific value ingedients (which made such a noticeable difference), but explosivity became a factor.

I'm sure this adds no value to our discussion. Jus' sayin'  . . .

[guzziart]

I don't notice any difference in running 87 up to 93 so I opt for the less expensive 87 stuff.  However, in the last year or so "Circle K" brand offers 90 octane non-ethynol, I notice a huge difference in starting/running performance with the non-eth stuff...same with my mower, string trimmer, chain saw, atv, generator, etc., I like it.  Prior to last year, non-eth was not readily availabile here in Northeast, Ohio, the fuel was all up to 10% ethynol.

Art

[Kevin_T]

Using ethanol is not a government conspiracy, it's very good at killing detonation. Today's engines really benefit from it's use. I think Guzzi wrote their standards before modern fuels. I don't venture too far from what they recommended. 

Just because you can't detonation doesn't it's not there. Might take microscope to bits of aluminum on your spark plug.

[audiomick]

22 hours ago, MartyNZ said:

 I wonder what the Moto Guzzi V11 fuel recommendation refers to? RON or (RON + MON)/2?

I have absolutely no doubt that they are talking about RON.

The petrol pumps here in Germany have the octane value quoted in ROZ.

https://de.wikipedia.org/wiki/Oktanzahl#ROZ

For those too lazy to translate for themselves, ROZ = RON.

Italy is EU, same as Germany, and such things are regulated here at the European Parliament level.

The fuel specs that Guzzi stated in the late nineties and early 2000s were certainly RON.

 

I did some searching and found this. It seems to have something to do with a Corvette.

http://www.auto-tests-service.de/Service/Technik/Allgemein/Treibstoffnormen_EU_US.html

Under "3. Stellungnahme"

it says

Quote

There is only a discrepancy between the specifications if both manuals mean the same thing by the term "octane". The octane number is determined in a single-cylinder CFR test procedure with a test engine. The fuel is compared with known fuels. Depending on the procedure, the octane number determined is referred to as the research octane number (RON) or the engine octane number (MOZ). The MOZ of a fuel is regularly significantly lower than the RON.

In Germany, the octane number is the so-called research octane number (RON). In the USA, octane rating is the arithmetic mean of RON and MOZ. The overview below compares the figures:

Translated with www.DeepL.com/Translator (free version)

Directly under that is a table showing ROZ (= RON), MOZ, and the US RON/MOZ calculation.

 

This Workshop Manual

https://guzzitek.org/gb/ma_us_uk/1100/V11_1999-2003_Atelier(Compil-GB-D-NL).pdf

specifies on page 20 that the V11 should be fuelled with "premium unleaded 95".

Referring back to the nice table on the Corvette site, that should be 90 in US numbers, and not that much higher than the 87 octane mentioned in the openeing post. So 87 in US numbers would likely not cause any great problems most of the time.

As a comparison: my V35 Imola is supposed to get minimum 97 RON. Awkward, as that doesn't fit into the modern standard very well. The lowest number available is 95, the next one up is 98. Ocasionally one lands at a petrol station that doesn't have the 98, so occasionally the Imola has to put up with the lower grade. To be quite honest, I have never noticed a problem with that. So I could imagine that US 87 would mostly not bother a V 11.

 

 

[LowRyter]

50 minutes ago, audiomick said:

I have absolutely no doubt that they are talking about RON.

The petrol pumps here in Germany have the octane value quoted in ROZ.

https://de.wikipedia.org/wiki/Oktanzahl#ROZ

For those too lazy to translate for themselves, ROZ = RON.

Italy is EU, same as Germany, and such things are regulated here at the European Parliament level.

The fuel specs that Guzzi stated in the late nineties and early 2000s were certainly RON.

 

I did some searching and found this. It seems to have something to do with a Corvette.

http://www.auto-tests-service.de/Service/Technik/Allgemein/Treibstoffnormen_EU_US.html

Under "3. Stellungnahme"

it says

Directly under that is a table showing ROZ (= RON), MOZ, and the US RON/MOZ calculation.

 

This Workshop Manual

https://guzzitek.org/gb/ma_us_uk/1100/V11_1999-2003_Atelier(Compil-GB-D-NL).pdf

specifies on page 20 that the V11 should be fuelled with "premium unleaded 95".

Referring back to the nice table on the Corvette site, that should be 90 in US numbers, and not that much higher than the 87 octane mentioned in the openeing post. So 87 in US numbers would likely not cause any great problems most of the time.

As a comparison: my V35 Imola is supposed to get minimum 97 RON. Awkward, as that doesn't fit into the modern standard very well. The lowest number available is 95, the next one up is 98. Ocasionally one lands at a petrol station that doesn't have the 98, so occasionally the Imola has to put up with the lower grade. To be quite honest, I have never noticed a problem with that. So I could imagine that US 87 would mostly not bother a V 11.

 

 

I run my LS-3 6spm Corvette with the cheapest 87 ethanol gas on the pump, same as my Honda Accord. I've never felt a difference in the power or heard a ping. 

Air cooled big twins, perhaps you take off in 2nd and don't know it....yeah.  BTDT.  clack clack...  Yeah, I baby my bikes, just because....I mean 4 gallons?    I'd never worry if I needed gas to go and cheap gas was all that's available.  I might granny the throttle a bit at first. I'd be more worried about the crap in the gas filter.

[Lucky Phil]

On 7/26/2023 at 11:13 AM, LowRyter said:

I run my LS-3 6spm Corvette with the cheapest 87 ethanol gas on the pump, same as my Honda Accord. I've never felt a difference in the power or heard a ping. 

Air cooled big twins, perhaps you take off in 2nd and don't know it....yeah.  BTDT.  clack clack...  Yeah, I baby my bikes, just because....I mean 4 gallons?    I'd never worry if I needed gas to go and cheap gas was all that's available.  I might granny the throttle a bit at first. I'd be more worried about the crap in the gas filter.

That's because the adaptive learning in the EFI system had adjusted the LTFT ( long term fuel trim) and ignition to adapt to the low octane fuel you run. It senses LAMBDA and knock and adjusts the ECU to cope with the fuel. If you pull the ECU fuse or disconnect the battery for 10 minutes and then reinstall preferably when the engine is at operating temp (so the idle relearn is faster) and null out all the learned 87 octane parameters and put some 91 octane in it you will feel it go MUCH better.

 

Phil