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Discussion Starter · #1 · (Edited)
I know it has probably been asked millions of times but I have just bought a new Thruxton and the dealer said to use premium (95 octane) although we have (98 octane) fuel available in OZ, ..it seems like a better idea to use better quality fuel..cleaner fuel cleaner motor..:confused:.any thoughts please?
 

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I know it has probably been asked millions of times but I have just bought a new Thruxton and the dealer said to use premium (95 octane) although we have (98 octane) fuel available in OZ, ..it seems like a better idea to use better quality fuel..cleaner fuel cleaner motor..:confused:.any thoughts please?
Use decent grade fuel (i.e., not the stuff off the back of a lorry out of a 20 L. bucket for a few pence cheaper...!) and the rated octane for the bike. Going with a higher grade is tossing $$ to the wind. Won't do anything for performance unless the engine is modified to need a higher octane. If the manual says 95 RON or 89 PON, go with it.

Used to work for a major oil company....the biggest differences were the detergent mixes which varied between the "cheap petrol" and the more expensive brands....but the base fuel was the same. DTW pricing (dealer tankwagon) variations were based on the additive packages that the customer got....we have a local brand that uses the same mix as Exxon (Esso) but they run a few cents cheaper per gallon due to their marketing costs being lower. Same fuel...no difference.

Derswede
 

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Discussion Starter · #3 ·
mmmmmm

Thanks for that....im still confused though as the manual says dont use less than 91 octane...its has no referance to what it would run best on...so what is the best octane to run my bike on....still not known and cant seem to get a straight answer out of triumph..
 

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#1 Octane rating is not an indicator of the quality of the gas, merely a means of measuring its anti-knock characteristics.

#2 If your bike is running EFI and is somewhat modern, it will have knock sensors that will retard the spark long before you hear any pinging. Sometimes, if you are using a low octane fuel, you will notice this in a drop in power and increased fuel consumption. If your bike is not so equipped, you may try running progressively lower octanes until you hear pinging and then go back up one level. You should really only notice this under heavy engine load.

#3 Triumph, and almost any modern engine maker, has already done this type of testing and publishes a recommended octane rating. Might as well listen to them. If they say 91 is minimum, that is what you should use.

#4 Try to stick with name brands of gasoline and try to use stations that move a lot of gas. It will reduce the probability of getting a tank of bad stuff.
 

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Shovelstrokeed, agreed. The major factor for octane rating for an engine is the compression ratio of the engine. The higher the compression ratio, more octane is needed for a slower burn. Do you happen to know what the compression ratio of the engine is? Is your engine computer controlled?

95 octane, if that is in fact what Triumph says, would lead me to believe that the comp ratio is up there in the 10:1-11:00 range if the engine is non-computer controlled, as I can usually get away with running up to 9.5:1 comp. on 89 octane at sea level without pinging in a non-computer controlled carbureted engine. My TT600 has 12.5:1 comp ratio and can run on 89 octane with no issues, but the computer allows for that with ignition timing and air/fuel ratio changes, as there is no way a 12.5:1 non-computer controlled engine would run well on 87 octane.

I agree that buying from either a large chain that sells a lot of fuel, or from a smaller chain or private station that you know sells enough to have new fuel delivered at least once a month is the wise way to go. The really cheap places are usually that cheap because they buy older fuel that is going/has gone bad, along with having tanks that aren’t as clean and flushed as say a higher consumption station.
 

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Bombfactory- pauliepaulie is referring to Aussie RON octane ratings, rather than US (RON+MON)/2 ratings, just in case the numbers weren't making sense.

Cheers,
-Kit
 

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Discussion Starter · #7 ·
Shovelstrokeed, agreed. The major factor for octane rating for an engine is the compression ratio of the engine. The higher the compression ratio, more octane is needed for a slower burn. Do you happen to know what the compression ratio of the engine is? Is your engine computer controlled?

95 octane, if that is in fact what Triumph says, would lead me to believe that the comp ratio is up there in the 10:1-11:00 range if the engine is non-computer controlled, as I can usually get away with running up to 9.5:1 comp. on 89 octane at sea level without pinging in a non-computer controlled carbureted engine. My TT600 has 12.5:1 comp ratio and can run on 89 octane with no issues, but the computer allows for that with ignition timing and air/fuel ratio changes, as there is no way a 12.5:1 non-computer controlled engine would run well on 87 octane.

I agree that buying from either a large chain that sells a lot of fuel, or from a smaller chain or private station that you know sells enough to have new fuel delivered at least once a month is the wise way to go. The really cheap places are usually that cheap because they buy older fuel that is going/gone bad, along with having tanks that aren’t as clean and flushed as say a higher consumption station.
Cheers for that, its for my 08 Thruxton 900...we havr regular which is 95 octane and premium, this is 98 octane, mostly use BP, i suppose I want to do best for the bike, not my wallet...just need to make sure using the higher octane atleast wont hurt my motor...Not sure what the compression ratio is..will look it up...appreciate your advise....pauliepaulie
 

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pauliepaulie, 95 octane is possibly the minimum rating you should use and the dealer insuring that you were aware of that. There should be some info in your Owner's Manual under General Information. Higher octane won't hurt and can be helpful when outside temperatures are high to prevent pre ignition.

Brad
 

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An Aussie reply

pauliepaulie, I was advised to use at least [/B][/U]95 ron and preferably 98 ron from BP or Mobil by the Triumph dealer for my Sprint which has a fairly high compression. If you were told at least 91 ron I would consider 95 ron where ever possible.
Most of the guys I ride with use only BP, Mobil or Caltex and I believe this is what was recomended by thier respective dealers. This covers a range of makes including Triumph and Ducati, and I am led to believe ther fuel is a better quality to Shell and have been warned off Optimax and its replacement.

Hope this helps.

Brendan
 
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