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High octane better or not ?

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René Alexander

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Beuningen Netherlands
Last trip in Germany we used high octane fuel (up to 102, Aral Ultra). Usually we use 95, standard in The Netherlands.

It felt....... better, better throttle response. Or is it only better in the "mind" of the rider ? :loco:

So i wonder: is high octane better or not ? :confused:
 
A Yamaha Outboard Motor School I went to many years back stressed on using only what you need to to keep the engine running smooth under load. The higher the octane, the more additives and money.
My '07 1250S Bandit runs just lovely on regular gas here in the US. My KLR , if I'm just loafing about , regular is fine, if hard on the throttle as in the mountains, I go to the Plus or Hi to combat pinging. Had to do the same on my old BMW Oilheads also.
 
Me and my riding buddies have all switched to premium fuels in our dual sport bikes, KLR's, DRZ's, etc. Main reason is that the premium fuels last longer in the tank when the bike is not being ridden as much, or they have caused us less problems then the regular fuels have in the past. We are also adding a fuel stabilizer and a injector cleaner to or fuels when the bikes are setting and not being ridden as much. If our US law makers don't quit adding additives to our fuels we will soon have a garage fully of bikes that won't run.

John
 
Using a higher octane fuel than what is recommended by the manufacturer, may produce more power in an engine which is operating under heavy load and high temperatures.

The higher the octane rating of gasoline, the less susceptible it is to pre-ignition caused by compression or high combustion chamber temperatures (knock or ping). Pre-ignition reduces engine power output and damages the internal components. Although many modern engines have an anti-knock system to retard ignition if pre-ignition is detected; this also reduces the power the engine will generate but saves the internals from damage.

The tendency for fuel to pre-ignite goes up with temperature and higher (open) throttle settings. Therefore, using a higher octane rated fuel may increase the load under which your engine will operate before the engine starts pinging or its anti-knock system retards the ignition timing.

Riding hard in the Ozarks on a hot day? Consider using a higher octane fuel.
 
95 octane seems pretty low to me for the Netherlands, given your altitude. In the US, 95 is common above, I'd say, 4,000 feet. Given that, I can see a real possibility of performance difference.

Around here, our standard unleaded (at 600 feet altitude) is 97 octane. I've tried premium gas in various cars and bikes over the years and couldn't tell the difference except in a couple of mid-eighties vehicles that were prone to predetonation and 'knocking'.
 
I used to have a spreadsheet on my work truck that spanned almost 500k miles.
I got better mileage with premium but it was only cost effective at a certain dollar amount.

On my Bandit 1250 I have ran regular 70% of the time. The other 30% is Premium while riding around the mountains or track days.

I do get better mileage with Premium and considering the small cost difference in comparing our tanks to the increased mileage I will probably switch to Premium.
 
In some lower compression engines (certain older motorcycle engines specifically), running hi-octane fuels can result in a build up of deposits on the valves and other parts. If you're running hi-octane in a motor that doesn't require it, I'd make sure to inspect the top end closely during valve adjustments and the like.
 
tshelfer said:
95 octane seems pretty low to me for the Netherlands, given your altitude. In the US, 95 is common above, I'd say, 4,000 feet. Given that, I can see a real possibility of performance difference.

Around here, our standard unleaded (at 600 feet altitude) is 97 octane. I've tried premium gas in various cars and bikes over the years and couldn't tell the difference except in a couple of mid-eighties vehicles that were prone to predetonation and 'knocking'.
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Different rating systems aside (US uses avg of RON and MON), higher altitudes with thinner air require less anti-knock which equates to lower octane numbers. Down here at the coast, the normal pump octane for premium is 93. When I was in Denver, the norm for premium was 90 or 91. Lo-test is 87 octane, not 97.
 
The idea that high-octane fuels have more energy is 100% false, and there's ample proof of it if you do a few google searches. Higher octane resists detonation more, period. In fact, higher octane gas typically has slightly lower energy content per volume.

In a few brands, higher octane blends MAY have more detergents than regular, and so may be better from that standpoint, but all major brand gasolines have adequate levels of detergent for modern engines in normal use. And, of course, if you can find a premium that's ethanol free you'll get more power and better mileage than an ethanol blend, but the reverse is also true. An ethanol free regular will be better than 10% ethanol premium, unless of your course your vehicle requires higher octane fuel.
 
dukey33 said:
Different rating systems aside (US uses avg of RON and MON), higher altitudes with thinner air require less anti-knock which equates to lower octane numbers. Down here at the coast, the normal pump octane for premium is 93. When I was in Denver, the norm for premium was 90 or 91. Lo-test is 87 octane, not 97.
Click to expand...

I never saw anything below 97 RON in Italy. Their "regular" is our hi-test or premium.
 
dukey33 said:
Different rating systems aside (US uses avg of RON and MON), higher altitudes with thinner air require less anti-knock which equates to lower octane numbers. Down here at the coast, the normal pump octane for premium is 93. When I was in Denver, the norm for premium was 90 or 91. Lo-test is 87 octane, not 97.
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You're absolutely correct, Dukey. I inadvertently added 10 in my head. Either I'm getting senile, or I've fallen without a helmet one too many times.
 
Yup bluestreak is spot on here...Higher octanes generally need more compression to get a complete combustion...Lower octanes actually combust easier which is why on a higher compression engine combined with too low octane you get the knocking as the fuel will begin to combust quicker and at the wrong time during the combustion cycle causing a knock and power loss...In the opposite scenario, low compression and high octane can lead to incomplete combustion and less power...I do know on a 2 stroke engine too much octane will make it run rich and reduce power as well.

So basically, more power will be had using the minimum octane needed for the compression ratio.
 
Similar to what GA-Bandit said,

I commuted with my Harley for a few weeks on regular gas, and then for the same number of trips using premium. The loss of mpg with the regular was in excess of the premium paid for premium. It mathematically came out advantageous to use premium. I then tried the same experiment with my Mini Cooper S, same result! I have not gone back to regular...

In addition, there was one hill, about 800' of elevation gain in about 3 miles on the way home from work. I would get the bike to 55 approaching the hill, and then click on the cruise control. In 5th gear, on premium, the bike would pull all the way and maintain speed. On regular, I had to down shift to 4th to get it to pukk the hill at 55.

So, almost a 15% increase in mileage, slightly increased performance, and less that a 12% increase in cost. Premium won!
 
The reason for the higher Octane in Germany and such is there oil is better then ours. That is why we came up the the super/turbo charger in WW1 and WW2 planes, we were getting killed by the Germans and there hi comp motors that we could not run due to our low octane fuel. Nevertheless, in Colorado the reg is 85, here in NM it is 86. Higher elevations have thinner air and reduce the Knock. I use higher octane when I sport ride to keep my motor a bit cooler but not for power. Dale has posted his dyno resultes on different types of fuel and he states that the B1250 runs better on the lower octane stuff. If you get some time it is an interestering read about octane and fuel refining in the 40's and how we used forced induction on our war planes to out fly the Germans.

Mark
 
Run what the manufacturer specs in the owners manual. The engineers that designed the motor have done the R&D with the proper equipment. I'd be hard pressed to believe that performance differences between grades and brands are not caused by some other additives or contaminants.
 
California said:
Similar to what GA-Bandit said,

I commuted with my Harley for a few weeks on regular gas, and then for the same number of trips using premium. The loss of mpg with the regular was in excess of the premium paid for premium. It mathematically came out advantageous to use premium. I then tried the same experiment with my Mini Cooper S, same result! I have not gone back to regular...

In addition, there was one hill, about 800' of elevation gain in about 3 miles on the way home from work. I would get the bike to 55 approaching the hill, and then click on the cruise control. In 5th gear, on premium, the bike would pull all the way and maintain speed. On regular, I had to down shift to 4th to get it to pukk the hill at 55.

So, almost a 15% increase in mileage, slightly increased performance, and less that a 12% increase in cost. Premium won!
Click to expand...



Ummmm,,,,, a Harley and a Mini both use high compression engines. Running regular on a consistant basis will wreck either engine. Mini forums are full of people griping about problems and short engine life and when the laundry is done a high percentage ran regular in them.

Harleys are expensive. They also have a reputation for being short lived. If one uses correct gas and does the meaningfull maintinence, they last a long time.

Don't short yourself.
 
mi1lertm said:
The reason for the higher Octane in Germany and such is there oil is better then ours.

Mark
Click to expand...

Hogwash! In the first place, Europe imports most of their oil, so even if your statement were true it would have little meaning. Second, US Texas sweet crude is the highest quality crude you can buy. Third, once it's refined into gasoline, it doesn't really matter what crude you started with. Lighter crude is easier to refine, but the final product doesn't matter. 95 RON is 95 RON, regardless of what crude you start with.

The real reason for higher octane in Germany (and most of the rest of the world) is very simple, and has nothing to do with crude. Europe uses Research Octane Number (RON) on the pumps. The US using an average of RON and Motor Octane Number (MON). Look on a US gas pump and you'll see octane defined as R+M/2. The two numbers come from different test protocols, and MON is always lower than RON, so the average of the two (Pump Octane Number or Anti-Knock-Index (AKI) in US parlance) will always be lower than the Euro spec RON number.

Geez, where do people come up with this misinformation? A quick Google search would have given you the facts.

Anyway, there's no direct equivalence between RON, MON, and AKI, but the numbers here provide a general idea:

http://en.wikipedia.org/wiki/Gasoline#Octane_rating

Different countries have some variation in what research octane number (RON) is standard for gasoline or petrol. In Finland, Sweden and Norway, 95 RON is the standard for regular unleaded petrol and 98 RON is also available as a more expensive option. In the UK, ordinary regular unleaded petrol is 91 RON (not commonly available), premium unleaded petrol is always 95 RON, and super unleaded is usually 97-98 RON. However, both Shell and BP produce fuel at 102 RON for cars with high-performance engines, and the supermarket chain Tesco began in 2006 to sell super unleaded petrol rated at 99 RON. In the US, octane ratings in unleaded fuels can vary between 86 and 87 AKI (91-92 RON) for regular, through 89-90 AKI (94-95 RON) for mid-grade (European premium), up to 90-94 AKI (95-99 RON) for premium (European super).
Click to expand...
 
Thanks for taking the time to clear that up. Another bit of common misunderstanding is the idea that premium gasoline contains more octane than regular. Octane would reduce the anti-detonation quality of gas.

A fuel with an octane rating of 90 performs like a mixture of 90% iso-octane and 10% heptane, in terms of anti-knock quality.
 
BlueStreak said:
Hogwash!
The real reason for higher octane in Germany (and most of the rest of the world) is very simple, and has nothing to do with crude. Europe uses Research Octane Number (RON) on the pumps. The US using an average of RON and Motor Octane Number (MON). Look on a US gas pump and you'll see octane defined as R+M/2. The two numbers come from different test protocols, and MON is always lower than RON, so the average of the two (Pump Octane Number or Anti-Knock-Index (AKI) in US parlance) will always be lower than the Euro spec RON number.
Click to expand...

Tell it like it is :clap::clap: I too was amazed at all the answers. Having worked for Shell Oil and shipping oil to the Norco Processing Plant where they made gasoline way back in the 60's , I was schooled on gasoline blending and manufacturing at an early age.
I did then and do now , pretty much follow manufactures recommendations. I once had a '67 Ford Fairlane 500 with a '69 Holman moody 427 in it. What ya think I had to run in that? This was before no lead stuff.
 
Since we're on the subject, I have something I've been wondering. From what I remember our bandits have 10.5:1 compression ratio. In the past this would require premium gas in cars to prevent issues. Some engines still need premium at this compression ratio. We can run our 10.5:1 Bandits on regular. What gives?
 
my 98 bandit 1200 and my 06 FJR 1300 both regular 87, both run great, of course the bandit I run an additive such as techron treatment every thousand miles to get rid of deposits. Now My 89 harley FXR factory recommended 89, of course i run 91 or 93 octane, as that 89 is a blend of 87 and hi octane, at the station and sometimes does not work out so well. unless you like to waste money or have bumped compression up, use the recommended gas. I hate ethanol blends they lower my fuel economy, and it is documented fact that alcohol added to fuels are less effecent.
 
BossMaverick said:
Since we're on the subject, I have something I've been wondering. From what I remember our bandits have 10.5:1 compression ratio. In the past this would require premium gas in cars to prevent issues. Some engines still need premium at this compression ratio. We can run our 10.5:1 Bandits on regular. What gives?
Click to expand...

Advances in combustion chamber design/shape. Computer controlled fuel injection and spark advance are the culprits. ;-) :trust:
 
BlueStreak said:
That 427 ran on E85, right? :lol2:
Click to expand...

:clap::clap: I was lucky enough to have an Amoco Station a few blocks from home. After reading a dyno test on gasolines by Dirt Rider Magazine way back in time, where Amoco Hi Test ( One of the first Lead Free gasolines ) a 250 two stroke Yamaha DT1 engine as the test mule , it made the most horsepower and run the coolest exhaust temp for gasoline being put out at that time. All other factors being equal. From Then ON, it went in my bikes and car from then on. :trust::trust:
 
BossMaverick said:
Since we're on the subject, I have something I've been wondering. From what I remember our bandits have 10.5:1 compression ratio. In the past this would require premium gas in cars to prevent issues. Some engines still need premium at this compression ratio. We can run our 10.5:1 Bandits on regular. What gives?
Click to expand...

Octane requirement is affected by many things - ignition timing, temperature, humidity, elevation, and possibly more I'll remember after I've had my coffee. Your bike probably has a knock sensor which will retard the ignition timing at the onset of detonation. Furthermore, all this really only come into play at high power demand or high Brake Mean Effective Pressure (BMEP). Don't twist the throttle hard and you'll never have a problem!
 
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