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premium versus regular gas

GT-Rx® said:
Most Guzzi recommend 95 RON. I always run premium, YMMV.

RON (Euro) = USA (AKI/PON)
91 = 87
93 = 89
95 = 91
98 = 93
Click to expand...
So Todd, would it be unadvisable for me to add 100 grade octane from pumps that I can go to here in Vegas.?? I believe the Rebel stations carry it due to all of the off-road guys heading out into the desert and also due to going out to the Friday night drag strip here at the Las Vegas Speedway.. Would a 100 grade damage my V7R..?
 
The higher the octane rating, the more resistant to compression ignition (ping). The higher the compression ratio of the engine, the higher the octane rating is required to eliminate ping. The lower octane rated fuel have been said to provide more energy upon combustion. So the answer is run the lowest octane rating you can without ping. Since the recommended octane is 91 octane, however the closest in the US is 93, so I'd run 93 octane. 100 octane won't harm the engine, but there is no added benefit unless you experience ping with 93 octane.
 
As John states above, little technically is to be had with running higher octane... However, I would bet you will enjoy the additional snap of the throttle with higher octane on a top off on occasion, provided you resolve the uber-lean (low throttle) OEM fueling.
John, FYI... Most of the Southwest (particularly CA) is shown at a maximum of 91 for premium. Rumor has it that there was a legal battle that capped the octane shown at the pump. Perhaps someone more knowledgeable then I on the subject can chime in.
Edit: You can get unleaded 100 octane at select stations in and around L.A.
 
GT-Rx® said:
As John states above, little technically is to be had with running higher octane... However, I would bet you will enjoy the additional snap of the throttle with higher octane on a top off on occasion, provided you resolve the uber-lean (low throttle) OEM fueling.
John, FYI... Most of the Southwest (particularly CA) is shown at a maximum of 91 for premium. Rumor has it that there was a legal battle that capped the octane shown at the pump. Perhaps someone more knowledgeable then I on the subject can chime in.
Click to expand...
Well, after 91, its sort of cents on the Dollar, Im pretty sure I have seen 93, or mebbe it was 98, on my travels.
Jeez gettin old sucks. It sneaks up on you & steals your memories !
Anyway, this year, as well as doing a fuel log, Ill try & note the octanes.
BUT; I REITERATE TO ALL & SUNDRY........
USING LESS THAN PREMIUM, & MY BREVA 750 STRUGGLES TO GET UP TO 55 MPH ,IN EVEN A SLIGHT HEADWIND !!
I am so old, I cannot hear PINGS, but my eyes are still perfect & I can see my revs and speed !
Anything less than PREMIUM, irrespective of 91 or 98, and I see & feel, a loss in VELOCITY !!
 
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GT-Rx® said:
As John states above, little technically is to be had with running higher octane... However, I would bet you will enjoy the additional snap of the throttle with higher octane on a top off on occasion, provided you resolve the uber-lean (low throttle) OEM fueling.
John, FYI... Most of the Southwest (particularly CA) is shown at a maximum of 91 for premium. Rumor has it that there was a legal battle that capped the octane shown at the pump. Perhaps someone more knowledgeable then I on the subject can chime in.
Edit: You can get unleaded 100 octane at select stations in and around L.A.
Click to expand...
Hi Todd,
Didn't know you guys suffer from low octane fuel in the Southwest.
In the the prairie states I've had trouble finding 93 octane. I've run 89 when the choice was pump it or push. I just didn't ask much of the bike until I could get 93 back in. So far 93 is still common in the east, and even some stations in the north east (Sunoco if you can find one) may have a 98 available.
 
Around here it varies, in some areas it is 93 octane premium and in other areas premium is only 91 octane. I can't say I have ever noticed a difference between them. In my travels I have been to areas of the USA where 89 octane was the highest available.
Another factor in this is altitude. If you are at higher altitude you do not need as high an octane as you would with the same motor at lower altitude to avoid ping/knock. When I found 89 was the highest available it was in the mountains and at that altitude you likely did not need anything higher.
As has been said, premium fuel does not make more power if the motor does not need it to prevent ping/knock. Running 100 octane fuel will not make more power if the motor does not need it to prevent ping/knock.
 
john zibell said:
The higher the octane rating, the more resistant to compression ignition (ping). The higher the compression ratio of the engine, the higher the octane rating is required to eliminate ping. The lower octane rated fuel have been said to provide more energy upon combustion. So the answer is run the lowest octane rating you can without ping. Since the recommended octane is 91 octane, however the closest in the US is 93, so I'd run 93 octane. 100 octane won't harm the engine, but there is no added benefit unless you experience ping with 93 octane.
Click to expand...
John, thanks for the input..I'll stick with the regular 91 octane that I've been using all along then and save myself the extra cents..!!
 
89 in my 13 V7
93 in my 79 Triumph
89 in my 85 BMW R80
89 in my 05 Triumph Thruxton
87 in my 11 Triumph tiger 800
no pings
 
Reviving an old thread here, but I'm a newbie to this forum so I have an excuse.

For the layman; Octane rating (for all practical purposes for us) refers to how difficult it is to set fire to the fuel. Higher octane = MORE difficult for set it on fire. Yes that's correct! Hence, if you're experiencing pinging you need to slow down the flame front in your combustion chamber, therefore, use a higher octane fuel. Contrary to what some have alluded, the calorific value (the energy) in the fuel is exactly the same. Using the lowest octane non-pinging fuel is going to be the best value for money and will provide all the performance your engine can offer. However, running a higher octane fuel gives just a slight safety margin for the odd bit of unplanned pinging, especially for those of us who are aging somewhat, and have difficulty hearing the pinging. Sorry
motoguzziman but I'd suggest that this is your problem. Pinging can rob a great deal of power, and can have catastrophic outcomes for your engine. For years I worked on aircraft, where pinging was death!

You won't lose ANY performance using an octane greater than you need. It'll just cost more at the bowser. My soon to be delivered Gutz V7iii will be my 1st ever FI bike (and my 1st Gutz). Having only ridden carburetted bikes so far I believe it's been money well spent to use one octane level above what the book says. Are the Gutz systems too agricultural to have a "knock" sensor?
 
Dale. The Guzzi system is pretty simple by FI standards. No "knock" sensors, no air mass sensor, (air mass estimated by air temperature and TPS value). Lambda change rates are low, plus Lambda value only impacts fueling to a specific RPM and not the entire rev range. Above a certain RPM the ECU control goes to open loop.
 
john zibell said:
Dale. The Guzzi system is pretty simple by FI standards. No "knock" sensors, no air mass sensor, (air mass estimated by air temperature and TPS value). Lambda change rates are low, plus Lambda value only impacts fueling to a specific RPM and not the entire rev range. Above a certain RPM the ECU control goes to open loop.
Click to expand...
So it's little more than an electronic carbuetter then.
 
Dinsdale Piranha said:
Reviving an old thread here, but I'm a newbie to this forum so I have an excuse.

For the layman; Octane rating (for all practical purposes for us) refers to how difficult it is to set fire to the fuel. Higher octane = MORE difficult for set it on fire. Yes that's correct! Hence, if you're experiencing pinging you need to slow down the flame front in your combustion chamber, therefore, use a higher octane fuel. Contrary to what some have alluded, the calorific value (the energy) in the fuel is exactly the same. Using the lowest octane non-pinging fuel is going to be the best value for money and will provide all the performance your engine can offer. However, running a higher octane fuel gives just a slight safety margin for the odd bit of unplanned pinging, especially for those of us who are aging somewhat, and have difficulty hearing the pinging. Sorry
motoguzziman but I'd suggest that this is your problem. Pinging can rob a great deal of power, and can have catastrophic outcomes for your engine. For years I worked on aircraft, where pinging was death!

You won't lose ANY performance using an octane greater than you need. It'll just cost more at the bowser. My soon to be delivered Gutz V7iii will be my 1st ever FI bike (and my 1st Gutz). Having only ridden carburetted bikes so far I believe it's been money well spent to use one octane level above what the book says. Are the Gutz systems too agricultural to have a "knock" sensor?
Click to expand...

Octane is not a measure of how hard it is to set fire to a fuel. It is a measure of how much pressure the fuel can take before self igniting / detonating. While that might seem like the same thing as how hard it is to ignite with a spark, it is not. Octane is also not a measure of how fast a fuel burns. A higher octane fuel may burn slower than a lower octane fuel, or it may burn faster. In the race fuel world there are high octane fuels that burn really fast.
But you are right that running higher octane fuel than you need is only wasting money. It isn't going to hurt your motor and it isn't going to make your motor run like a dog.
 
Of course, you're absolutely correct. I was giving a very potted precis "For the layman ..." using ordinary pump fuels. It's very difficult to get the message across to people that higher octane does not mean more power, in every-day riding of every-day bikes.

I hope you didn't take exception to my referring to your hearing problems, re pinging. I have the exact same problem, hence the reason why use higher octane fuel than specified. I have seen, a couple of times, the result of pinging. The most memorable being a Leyland 3.5l V8 which looked quite literally like if had exploded. 2 pistons had exited the block, destroying all of the engine and much of the other stuff in the engine bay. The Rover was written off.
 
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Dinsdale Piranha said:
Of course, you're absolutely correct. I was giving a very potted precis "For the layman ..." using ordinary pump fuels. It's very difficult to get the message across to people that higher octane does not mean more power, in every-day riding of every-day bikes.

I hope you didn't take exception to my referring to your hearing problems, re pinging. I have the exact same problem, hence the reason why use higher octane fuel than specified. I have seen, a couple of times, the result of pinging. The most memorable being a Leyland 3.5l V8 which looked quite literally like if had exploded. 2 pistons had exited the block, destroying all of the engine and much of the other stuff in the engine bay. The Rover was written off.
Click to expand...
I did not "take exception" to anything you posted. And I did not mean to sound harsh in my response. I just hate it when people confuse octane with anything other than what it is. It is something of a pet pev of mine. No worries.
And I am older and my hearing isn't so good either. My motorcycles use relatively little fuel, so using higher octane fuel does't really make a big difference cost wise, and it can be cheap insurance. As long as, like you said, you don't think it is going to make any more power with higher octane fuel.
Funny thing, our smart car requires high octane fuel. But it also uses relatively little fuel, and the difference for a tank of gas to use premium vs regular is usually only a few bucks, about twice what it cost for the motorcycles.
 
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