91 vs. 93 octane fuel?

[FLTRI]

91 octane is the highest you can buy locally. I know this is the minimum grade for my R12RT, with 93 recommended.

 

Anyone think it's worth the trouble to carry around a bottle of octane booster to bump it up to 93?

 

TIA

Dan

[Paul Mihalka]

Forgitaboutit. 91 is perfect and is all the bike needs. Even 89 may be OK. You won't gain anything with 93 or Octane booster.

[jakfrost]

I have been using 87 here on occasion when the ethanol octane 89 is unavailable. Living in the 'boonies' has its limitations, 'premium' is only available in the city.

 

So using my bike to commute to and from work, total of 200kms per day, I find the only difference is there is a purely subjective sense of slightly less 'omph' in the 6,000 rpm+ range, and, the computer says the total fuel range is on average about 30-40 kms less using 87 vs 91.

 

The EFC seems to sense octane and adjust the ignition accordingly, preventing pre-ignition or 'knock', just as advertised.

[stubblejumper]

have been using 87 here on occasion when the ethanol octane 89 is unavailable. Living in the 'boonies' has its limitations, 'premium' is only available in the city.

 

Personally,I refuse to use any ethanol blended fuel,as it has less energy per volume,which results in less lies per gallon.

[BigAdv]

In most countries (including all of Europe and Australia) the "headline" octane that would be shown on the pump is the RON, but in the United States, Canada and some other countries the headline number is the average of the RON and the MON, sometimes called the Anti-Knock Index (AKI), Road Octane Number (RdON), Pump Octane Number (PON), or (R+M)/2. Because of the 8 to 10 point difference noted above, this means that the octane in the United States will be about 4 to 5 points lower than the same fuel elsewhere: 87 octane fuel, the "regular" gasoline in the US and Canada, would be 91-92 in Europe. However most European pumps deliver 95 (RON) as "regular", equivalent to 90-91 US (R+M)/2, and even deliver 98 (RON) or 100 (RON)

 

Earl

[stubblejumper]

In Alberta the general standard at the pumps is:

 

87 octane with up to 10% ethanol

 

89 octane with up to 5% ethanol

 

91/92 octane with no ethanol

 

In British Columbia,you can also buy 94 octane in some locations.

[Paul Mihalka]

have been using 87 here on occasion when the ethanol octane 89 is unavailable. Living in the 'boonies' has its limitations, 'premium' is only available in the city.

 

Personally,I refuse to use any ethanol blended fuel,as it has less energy per volume,which results in less lies per gallon.

In the USA there are areas where you can't find anything BUT ethanol blended gas.

[chaparral]

I have used 89 octane at sea level on a 2000 2000RT I now live at 5,000' and use 87 on a 2005 RT. I still go to 89 along costal riding.

Octane is primarily a ping inhibitor; I believe the RTs have a knock detector that retards the spark until the ping is gone. I have only heard a ping once on the 05 whilst passing uphill. Lower gear cured it. Course I didn't twist the throttle to WFO. Ethanol is a octane booster/ping retarder but mileage suffers. my 2 cents.

[stubblejumper]

Octane is primarily a ping inhibitor; I believe the RTs have a knock detector that retards the spark until the ping is gone.

 

I wonder just how long it takes the computer to advance the timing after it is retarded.Retarding the timing will likely reduce fuel mileage,so using a lower octane fuel might not save you any money in the long run.

[TomfromMD]

 

Paul, I'm not far from you in Silver Spring (and was buying corn from a fellow in Sykesville to help heat my home until it got too expensive). Do you know of any stations in our area selling ethanol free (93 octane) gas? Thanks.

Tom

[JohnBeaven]

 

Regular here is 92RON, premium is 95RON, and Ultr is 98RON.

 

I use nothing but the Ultra. Even though it is more expensive, the price difference is bugger all over distance when you are only comsuming 4.9L/100km.

[JayW]

 

Anyone think it's worth the trouble to carry around a bottle of octane booster to bump it up to 93?

 

 

I don't.

[ShovelStrokeEd]

My Blackbird, which is equipped with a knock sensor, gets about 2 mpg better fuel consumption on 91 octane as opposed to 89. Given the average 0.20 price differential, I actually save money by running the premium. About $0.10/hundred miles.

[motoguy128]

have been using 87 here on occasion when the ethanol octane 89 is unavailable. Living in the 'boonies' has its limitations, 'premium' is only available in the city.

 

Personally,I refuse to use any ethanol blended fuel,as it has less energy per volume,which results in less lies per gallon.

In the USA there are areas where you can't find anything BUT ethanol blended gas.

 

I agree... in many parts of the midwest, you could risk running out of fuel. I do notice a drop in mileage using fuel with ethanol... more than the $0.10. gallon I'm saving. I do try to use premium without ethanol.... but I'm not going ot make an extra stop on a trip just to avoid it.

[stubblejumper]

I certainly would not risk running out of fuel to avoid ethanol,but when given the choice,I do avoid using it.So far,it hasn't been an issue where I live.

[Crank]

Anyone heard this before?

 

I have a friend who "has a friend" in the gas/refining business and who has told my friend that the only 3 gas stations that you want to buy from is Mobil, Shell or Citgo. The reason is their level of boosting/cleaning additives is better, and because the additives are mostly non-existent from other providers.

 

I am skeptical. Anybody hear this?

 

 

[motoguy128]

Anyone heard this before?

 

I have a friend who "has a friend" in the gas/refining business and who has told my friend that the only 3 gas stations that you want to buy from is Mobil, Shell or Citgo. The reason is their level of boosting/cleaning additives is better, and because the additives are mostly non-existent from other providers.

 

I am skeptical. Anybody hear this?

 

 

While there could be some truth to this, I wonder is the extra additives make much difference, and it's noteable that in many cases these 3 charge a small $0.05-0.10 premium for their fuel.

 

So is it better to pay $25-$50 over 20,000 miles for better additives, or use 1 bottle of fuel treatment/cleaner for $10-$15 over the same period that you may want to use anyway?

[R4ND0M_AX3]

The problem with relying on the knock sensor to tell the the ECM/ECU/BMS-K to pull timing is that it first has to knock. I have a history of doing bad things to rod bearings. I don't need any more help.

[FLTRI]

Thanks for all the replies. I figured the engine had a knock sensor.

 

Since the knock sensor retards the timing to prevent predetonation, wouldn't running 93 advance the timing back to where the engine was designed to run? And if the sensor is adjusting the timing to prevent knock when running 91 octane, wouldn't there be an associated decrease in performance?

 

I guess my real question should have been is the decrease in performance (by retarding the timing) between 91 and 93 octane enough to notice?

[motoguy128]

 

I guess my real question should have been is the decrease in performance (by retarding the timing) between 91 and 93 octane enough to notice?

 

I think there is a very small improvement in mileage and I might have noticed a small gain in power, but not that much. I don't spend a lot of pushing the engine to it's limits. My passenger prefers when I ride smooth, so WOT applications aren't too frequent.

 

I generally pruchase hte best octane available, but my choice of gas stations depends on timing, conveneince if it looks to have a descent convenience store and restrooms.

[GoldenK9]

Very Interesting! Here in Northern California it has always been the norm to run Chevron Premium (91 Oct) in all of your toys and high performance vehicles because it contains "Techron", I guess one of the best additives you can get. Next would be either Union 76 or Shell. All of the other brands are probably OK, just thought of as being substandard.

I have a friend, and former customer, who works for the gasoline distribution facility here in Chico (where the gas comes in from the refinery in its raw, base state) and he told me the gas is all the same (no label) until they add the specified chemicals, or additives, for each brand as it is loaded into the tankers for the trip to your local gas station.

[R4ND0M_AX3]

Since the knock sensor retards the timing to prevent predetonation, wouldn't running 93 advance the timing back to where the engine was designed to run?

I'm not sure how our bikes handle it. I do know how my car handles it. Timing is incrementally pulled on the short term under certain conditions when the knock sensors detects knock. This short term timing correction is eventually returned to normal as the ECU tries to see if it still knocks. Bascily 'riding the knock sensor' when bad gas is used.

 

And if the sensor is adjusting the timing to prevent knock when running 91 octane, wouldn't there be an associated decrease in performance?

Yes.