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Joined: Mar 2010
Posts: 3,581 Likes: 85
Moderate or good, occasionally poor Talk Morgan Addict
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Moderate or good, occasionally poor Talk Morgan Addict
Joined: Mar 2010
Posts: 3,581 Likes: 85 |
Somehow people always translate higher octane equals more power.
That is not true. A quick Google search for "octane and performance" brings up plenty of evidence that it is true, at least to an extent. If you want some heavy reading try downloading the PDF report here: Effect of Octane on Performance, Energy Consumption and Emissions of Two Euro 4 Passenger CarsQuote: " The best agreement between performance and fuel octane number was found using an Octane Index [(1-K).RON + K.MON] with a K-value of minus 0.6 or even more negative.". So now you know.
2011 Morgan 4/4 1932 Austin 7 Chummy
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Joined: Oct 2012
Posts: 2,776 Likes: 59
Talk Morgan Expert
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Talk Morgan Expert
Joined: Oct 2012
Posts: 2,776 Likes: 59 |
Somehow people always translate higher octane equals more power.
That is not true.
Octane is simply a measurement that indicates how quickly the petrol will ignite. Higher octane ignites slower than lower octane. When vaporized fuel is put under pressure with ambient heat it will eventually ignite. That is how a diesel engine works. So higher compression engines need higher octane fuel or they will pre-ignite.
Now it is often the case that higher compression engines are also higher performing, or have more power. But that is because of the engine, not the octane of the fuel. If you put high octane fuel into a YUGO, you still only have a yugo. Basically true and at one time simply true. In these days of electronic engine management, knock sensors and such like you are likely to find that an engine will give more power and better mileage on higher octane fuel as the feedback loops will alter various parameters to give best running on the fuel being fed into the engine. Can make a big difference on turbocharged engines, generally less of a difference on naturally aspirated. Did do some testing on bike engines on a dyno a long time ago and we found that the super unleaded of the day made for something like an improvement of 2% on power over normal unleaded but this was on highly tuned by car engine standard engines. Also found that one brand of octane booster made a similar difference on top of that 2%. Can't honestly remember which brand it was but it was based on toluene.
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Joined: Nov 2013
Posts: 1,944
Talk Morgan Enthusiast
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Talk Morgan Enthusiast
Joined: Nov 2013
Posts: 1,944 |
I did run super unleaded for several tanks full on my standard engine with just the bafflectomy. I did not notice any performance advantage & a very slight reduction in fuel consumption but not enough to offset the higher fuel cost. Now I use regular unleaded E5.
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Joined: May 2012
Posts: 1,789 Likes: 3
Talk Morgan Enthusiast
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Talk Morgan Enthusiast
Joined: May 2012
Posts: 1,789 Likes: 3 |
Easily get 40 mpg with Tesco Motillium 99 and it’s a sensible price.
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Joined: May 2019
Posts: 158 Likes: 1
L - Learner Plates On
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L - Learner Plates On
Joined: May 2019
Posts: 158 Likes: 1 |
My mechanic recommends putting in 100 octane fuel when I put the car away for the winter. He contends that's better than any of the gas treatments. It'll start right up in the spring. He puts that in any gas engines that he stores over the winter. I can get it at one local station here. The only problem is it's $ 7.00 a gallon !
Dutch Junge 194 Mound St Logan, OH USA 43138
2012 3 Wheeler 1980 + 8
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Joined: Jul 2018
Posts: 1,031 Likes: 2
Has a lot to Say!
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Has a lot to Say!
Joined: Jul 2018
Posts: 1,031 Likes: 2 |
That's a good price for 95 octane fuel over here!
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Joined: Mar 2015
Posts: 902
Talk Morgan Regular
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Talk Morgan Regular
Joined: Mar 2015
Posts: 902 |
Just a thought, has anyone tried Avgas LL 100 octane???
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Joined: Feb 2019
Posts: 3,854 Likes: 2
Talk Morgan Addict
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Talk Morgan Addict
Joined: Feb 2019
Posts: 3,854 Likes: 2 |
My mechanic recommends putting in 100 octane fuel when I put the car away for the winter. He contends that's better than any of the gas treatments. It'll start right up in the spring. He puts that in any gas engines that he stores over the winter. I can get it at one local station here. The only problem is it's $ 7.00 a gallon ! Where do you get it? Back 50+ years ago when ga was really gas and not something concocted by a corn farmer with a degree in chemistry 101 or 102 octane was available and I ran all my bikes on it as well as my sports cars.
The light at the end of the tunnel is actually a train. 2019 M3W
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Joined: Oct 2012
Posts: 2,776 Likes: 59
Talk Morgan Expert
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Talk Morgan Expert
Joined: Oct 2012
Posts: 2,776 Likes: 59 |
Just a thought, has anyone tried Avgas LL 100 octane??? Won't do the cats any good and will poison the Lambda sensors too.
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Joined: Feb 2019
Posts: 3,854 Likes: 2
Talk Morgan Addict
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Talk Morgan Addict
Joined: Feb 2019
Posts: 3,854 Likes: 2 |
Just a thought, has anyone tried Avgas LL 100 octane??? Won't do the cats any good and will poison the Lambda sensors too. Probably true. I was using it before computers existed.
The light at the end of the tunnel is actually a train. 2019 M3W
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