Bandit Alley
FAQ TOPICS => GENERAL MOTORCYCLE FAQ => Topic started by: Sven on September 09, 2005, 01:20:07 PM
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So, with gas prices continuing to escalate (and probably will for the rest of our lives), what's the general consensus:
1) Which grade do you normally run
2) Have you changed due to the price increases?
I know el Bandidos :bandit: can run lower octane, but most of the folks I know (on various bikes) buy the higher octane.
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I always run premium with my bikes. Although im told its a waste?? I dont change grades per prices....the differance when your only buying 5 gals or so, isnt that much.
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I run 94 octane premium in all my vehicles. Regarding octane, I'm just not sure what to ever believe about the value of it, although I've had a car where an obvious improvement in noise and performance came from upgrading to premium.
Some people say it's a waste; that there's no benefit. Others, including the manual for my Audi A6, specifically say to use premium.
I would really like to know "THE" answer on this, but all I expect is anectodal evidence. Who can you trust? :grin:
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I wonder if the deciding factor is the vehicles compression ratio ??
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My simple understanding of the octane issue, is simply if your vehicle has a high compression ration (9.5:1) or higher than you probably need it. If not then you don't. If you are running higher octane than necessary your engine runs less efficient because it is trying to burn off the extra Hydrocarbons, thus increases emissions, and reduces fuel economy and reduces power (granted all of this is very minute.)
I run 87 in all vehicles ('03 Suburban, '00 Impala, '99 Bandit)
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It's pretty simple. Octane is a combustion inhibitor. The higher the octane the less volatile the gas is. That is why in high performance engines that run at high temperatures and more importantly high compression ratios, high octane is needed to keep it from combusting too early. It does not make more power or clean your engine or anything else. In fact you want to ideally run the minimum amount of octane that allows you engine to run w/o "knocking", or having the fuel detonate before the piston reaches top dead center.
SO, a B12 with 9:1 compression ratio can run on regular unless it's really hot and under heavy load. I say that because I could get mine to knock, so I ran 89 octane and it was perfect. There was never a need or point in running premium.
How "hot" your sparkplug is can also play into it somewhat.
You didn't mention if your Audi has a 1.8T, but that's what's in my Passat and I always run 93 in it. Although Turbo engines almost always run much lower compression ratios as tested, the effective compression ratio goes way up once you come on boost. Thus it needs premium. You can run 89 or even 87 because the knock sensors will retard the timing enough to let you get away with it, you will lose power and MPG to the point where it doesn't make it worth it financially. Also in the case of VW/Audi and most other high end brands, any engine damage that results from lower octane fuel will void your warranty. They can test the fuel and also read the fault-code off the VAG-COM when they do the diagnostic.
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It's pretty simple. Octane is a combustion inhibitor. The higher the octane the less volatile the gas is. That is why in high performance engines that run at high temperatures and more importantly high compression ratios, high octane is needed to keep it from combusting too early. It does not make more power or clean your engine or anything else. In fact you want to ideally run the minimum amount of octane that allows you engine to run w/o "knocking", or having the fuel detonate before the piston reaches top dead center.
SO, a B12 with 9:1 compression ratio can run on regular unless it's really hot and under heavy load. I say that because I could get mine to knock, so I ran 89 octane and it was perfect. There was never a need or point in running premium.
How "hot" your sparkplug is can also play into it somewhat.
You didn't mention if your Audi has a 1.8T, but that's what's in my Passat and I always run 93 in it. Although Turbo engines almost always run much lower compression ratios as tested, the effective compression ratio goes way up once you come on boost. Thus is needs premium. You can run 89 or even 87 because the knock sensors will retard the timing enough to let you get away with it, you will lose power and MPG to the point where it doesn't make it worth it financially. Also in the case of VW/Audi and most other high end brands, any engine damage that results from lower octane fuel will void your warranty. They can test the fuel and also read the fault-code off the VAG-COM when they do the diagnostic.
Well, you're the expert as far as I'm concerned, so it's gonna stay premium in both the Audi A6 (2.8) and the Saab 9-5 (3.0). Would you say it's not necessary in a Ford Taurus SE Wagon? I think it's a 3.0 engine.
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Yeah, the Ford would run best on regular for normal driving. If you are really hot doggin' it or towing, you should run 89, but that's a big IF.
The 2.8L Audi V6 runs 10.3:1 compression and should get 89 minimum but safer with 91, 92, or 93 as it calls for.
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I think Manny covered it well (and there's plenty of threads on this subject here).
While he's needed to use midgrade in his B12 in the hot & humid clime of Atlanta, I've never had to move up from regular in the cooler climate of the Pacific Northwet (sic).
Use what the owners manual tells you to. If it tells you to use regular, use regular. If it tells you to use something else, use that. If you experience pinging, then step up a grade. If you're alreadyat the highest octane available, you need octane booster.
As for the Taurus, if you don't have the O/M, check the sticker near the fuel filler, it should tell you. Most cars in the US these days that do require premium will even tell you so on the gas gauge.
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Well, based on the good info here...i will be switching to regular. :bslap:
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Unless your bike is out of tune for some other reason... putting anything more than 87-octane in a Bandit is akin to overfilling a water glass because you want to make sure you have enough water.
It don't do no good. Once you have enough octane to prevent detonation... anything more is just donating more of your money to the poor ol' gas companies.
Even so... I've played around with various octanes & brands just out of curiousity... and I keep finding that it runs better on no-name brand 87-octance than it does on name-brand 93-octane.
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The one thing I do avoid is running gas with alcohol in it. Around here, that's Arco regular & midgrade and Union 76. They are required to tell you on the pump, so look for a sticker if you're in doubt. Alcohol can lead to faster erosion of jets, injectors and tiny fuel system passageways.
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I use 88 octane in my b12. Gas here is 86 88 90.
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I use 88 octane in my b12. Gas here is 86 88 90.
I'd go with 88 too in that case.
Wow... 90 octane is your premium? That kinda sucks since a lot of cars (Like my wife's Beemer) requires 91 or higher octance.
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His gas has lower octane because he's at a higher altitude and you need less octane at higher altitude.
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89
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87 is called "Regular" up here in Beaver Land. It seems to work fine in my 98 1200S Bandit. A couple of times the engine was quite crabby, (rough running), on a particular tank. I believe it was just a bad batch of fuel. As I understand it, using a higher grade than your owners manual calls for is a just a waste of money.
However. My manual calls for premium for its 9.5 compression ratio. Up here, the greedy oil companies demand 32 US cents a US gallon, 10Cdn cents a litre Extra for premium fuel! ... and our government is greedier in fuel taxes and many other taxes.
A few days ago Regular was $1.35Cdn per litre -the equivalent approx. of $4.35US per US gallon! :shock:
This is what led me to try "Regular" quite early. It worked as I haven't detected knocking.
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His gas has lower octane because he's at a higher altitude and you need less octane at higher altitude.
I'm only at 3200 feet...
Ya, it does suck for the vehicles that need 91+. Guess you go to Wally World and buy octane booster. :wtf:
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I have a B6 and I run Regular = 87 octane. I've been happy with it. My bike runs fine on it. I live in central Florida and drive half and half, stop-n-go and highway. The temps here get into the 98-99 degree range from July thru Sept.
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This is something on this topic I found on http://www.motorcycleperf.com
There is some other topics in there tech tips.
update on bad gasoline article
One of the most frequently encountered problems this season is the issue of “bad gas”. While not involving flatulence, it just as big a problem.
We have had more fuel-related problems ranging from poor starting, hesitation, etc. to just plain “quit and won’t restart” this year than in any of the past 25 years we have been here.
A further explanation of the two different areas of concern with gasoline may be in order for those who wish to pursue it.
1.) OCTANE
This is the resistance to detonation the gasoline offers. The most common grades of gasoline are: REGULAR at 87 Octane; MID-GRADE at 87-90 Octane; PREMIUM at generally 93 Octane. Other custom-built racing gasolines can offer up to 125 Octane. Octane is an indicator of the speed at which the gasoline burns in the engine.
The higher the octane, the slower the speed of the burn; the lower the octane the faster the burn. If the burn is too fast, uncontrolled combustion can occur. This most often is heard as “pinging” and is commonly referred to as detonation. This is because instead of burning through top dead center of the combustion stroke, the entire charge is ignited too early and explodes in the chamber and acts as a bomb. Conversely, if the speed of the burn is too slow, it continues after the useful work can be done in the motor and manifests itself as poor throttle response, reduced power output and increased emissions and fuel consumption. An engineering fact: THE MOST HORSEPOWER IS MADE AT THE THRESHOLD OF DETONATION. We have often gained horsepower on the dyno and felt improved starting and driveability going from Premium grade gas to Regular. This change was recently quantified in a customer’s Ducati M900 by reducing the cranking time to start-up from 15 to 3 revolutions, although part of the improvement is explained below.
The multi-valve combustion chambers and their reduced flame front propagation distances in the modern engines virtually eliminates the need for high-octane gasoline.
2.) COMBUSTIBILITY
This is the ability of the gas to burn. As mentioned above, gasoline needs to burn to be of any value in the motor. Modern gasoline has been subject to formulation restrictions that now make it able to sit only 4 to 6 weeks after manufacture before its usefulness as a fuel is compromised due to reduced combustibility. This is basically a separate issue from the speed of the burn as controlled by octane.
The biggest issue is the fact that the “volatiles” in this new formulation evaporate very quickly.
The reason these “volatiles” are so important is that they are the part of the gasoline that affects starting and throttle response. That is why you can often feel the difference between individual tanks of gas when it comes to starting, cold running and acceleration at lower rpms. The evaporation of these volatiles leaves a thicker, more viscous residue that becomes difficult for the carburetor to break up into combustible droplets. This sludge will adhere to the intake runner walls or goo its way into the combustion chamber.
The poor burning characteristics can be seen in the accompanying photo.
This difference becomes more pronounced with carbureted bikes using a hemi-style engine design (Harleys, Viragos, BMW, Ducati, etc.) as opposed to 4-valve and/or fuel injected motors.
One of the recurring themes in these problems has been the use of Premium gasoline.
There are no 4-valves bikes made in the last 20 years that need premium gasoline for normal street use. Very few of the 2-valve bikes need it either. One of the problems with premium is the fact that it is not used as much and sits in the ground much longer than the other grades, with the attending evaporation of the volatiles present at manufacture. This coupled with the more efficient combustion chambers used today makes the problem even worse. A second issue is the different ways used to achieve that higher octane. Each company has a different formulation, and with the high horsepower to displacement ratios of the newer bikes, tuning for this can be an issue.
A good rule of thumb is if the bike doesn’t ping and runs acceptably with regular, DON’T use Premium. Regular is sold faster, is fresher and will generally start easier and have better throttle response than the higher octane gasolines. Not nearly as many cars use premium as they can compensate for the lower octane of regular with built-in detonation sensors to compensate for the octane, thus reducing the amount of premium sold. Most underground tanks hold in excess of 4,000 gallons of gas, so with primarily motorcyclists buying it three or four gallons at a time, it will be there quite awhile. Also as the level in the tank drops it affords more opportunity for the volatiles to evaporate. It doesn’t matter what the owner’s manual or your friends say. We have often GAINED horsepower on the dyno when we took away octane.
We have had to make arrangements to properly dispose of all the gas that makes a bike run terribly, but works fine in a car or truck. So try a tankful or two of regular and see how the starting and performance changes. If the bike is unhappy, go back to what you were using before, but bear in mind the information here and be ready to switch if things change.
A good way to avoid problems such as this is to be certain you buy gasoline at a name-brand station. The neighborhood convenience store buys gas from a broker, so you have no idea what it is. That gasoline is purchased by price, not specification. Also do not use ethanol-dosed gasoline, as it can be very reactive with the metal used in carburetor bodies. Brand name stations have much more control over the product they sell. We use Amoco Regular as our baseline gasoline in the shop due to convenience, but occasionally make the trip to Shell for what a lot of our customers have said gave the best results in their bikes, especially the twins. Sealed containers of VP gasoline (some costing $42 per gallon) is another alternative, although cost prohibitive.
Remember- always buy brand name fuels to reduce the potential entertainment that accompanies poor quality gasoline.
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even with an advancer, jet kit & slip-on, 87 is fine, even in 100 degree summers in Okla CIty...I use 86 in the mountains....the only time I ever had problems was in hot muggy traffic at Daytona and it was pinging pretty bad, I did switch to premium.....
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A good rule of thumb is if the bike doesn’t ping and runs acceptably with regular, DON’T use Premium. Regular is sold faster, is fresher and will generally start easier and have better throttle response than the higher octane gasolines.
We use Amoco Regular as our baseline gasoline in the shop due to convenience, but occasionally make the trip to Shell for what a lot of our customers have said gave the best results in their bikes, especially the twins.
My sentiments EXACTLY. I use Amoco (BP) or Shell regular only... unless I'm stuck where I can't get it.
(FWIW... I've found Mobil gas is the worst, in my bike and cars, which is odd considering I'm completely sold on Mobil1 oil.)
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(FWIW... I've found Mobil gas is the worst, in my bike and cars, which is odd considering I'm completely sold on Mobil1 oil.)
That IS odd considering Mobil is owned by BP.
We don't even have Mobil stations around here anymore, they all changed to BP years ago.
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even with an advancer, jet kit & slip-on, 87 is fine, even in 100 degree summers in Okla CIty...I use 86 in the mountains....the only time I ever had problems was in hot muggy traffic at Daytona and it was pinging pretty bad, I did switch to premium.....
The problem with what you say here is that "pinging" is usually only audible and problematic under heavy load/throttle. If you heard it in traffic at Daytona where you were presumably just cruising around I'd be pretty damn concerned! :shock:
Unless you have some phenomenal hearing, I have a hard time with anyone hearing pinging on a bike with a slip-on and wind noise to boot. I was barely able to hear it on my bike when it was still stock, and then only under the following conditions:
~warm weather
~3-4th gear
~full throttle roll on @ 2-4000rpm
~leaning off the bike with my ear near the valve cover
It always did it with regular of any brand and didn't with mid-grade of any brand. This was sufficient and there was no need to switch to premium.
Although many Bandits may run fine on regular, bikes vary and people's ability to pick up on issues like pinging vary even more.
A bike that was not broken in properly or has tons of miles on it may very well have .5:1 lower compression and that IMO is enough to prevent pinging on regular.
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A bike that was not broken in properly or has tons of miles on it may very well have .5:1 lower compression and that IMO is enough to prevent pinging on regular.
Likewise, that bike may have higher compression from carbon buildup and require a higher octane. The other bad thing about carbon buildup is the carbon can get hot enough to glow and cause preignition from the hot carbon setting of the fuel mixture.
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An engineering fact: THE MOST HORSEPOWER IS MADE AT THE THRESHOLD OF DETONATION.
Then why is ignition always before top dead center?
When the compressed mixture inside a cylinder is ignited it takes time for the flame front to reach the piston and for the expanding gases to start pushing it down. The time that this takes changes according to a number of variables such as mixture strength, how well the cylinder has filled (dependent on volumetric efficiency and throttle opening), compression ratio and combustion chamber shape. Given the same circumstances of mixture strength, cylinder filling and CR, the time taken for the mixture to fully ignite and burn is the same regardless of engine speed. At increasingly higher RPM however, the time available for this burn to take place is correspondingly less, so it follows that you have to start burning the mixture earlier in order for it to push on the piston at the right time. This is the basis for increasing ignition advance.
Too much of this and the burning mixture hits the piston as it rises (pinking or pinging), too little and the flame front reaches the piston far too late and does not do a good job of pushing the piston down and the engine behaves like a herd of turtles. One of the reasons a diesel engine does not perform at higher RPM is that it has compression only ignition, so there is no way to increase the effective ignition advance.
So the engineering "fact" clearly does not apply to gas internal combustion engines. It's also a good example of why I never got the 5* advancer. It's not what you want for a torque happy street bike, though I'm sure it's great for a race/drag bike that spends it's life near redline.
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Manny, that would be exactly why you would have spark before TDC.
It's not ALWAYS before TDC... I had two Audis that fired 3* after.
They both used the same engine found in Rabbits, Golfs & Dashers.
(OTOH, it was a common hop-up trick to advance their timing 10*)
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Manny, that would be exactly why you would have spark before TDC.
It's not ALWAYS before TDC... I had two Audis that fired 3* after.
They both used the same engine found in Rabbits, Golfs & Dashers.
(OTOH, it was a common hop-up trick to advance their timing 10*)
But it suggests you should have 0* timing, doesn't it?
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The other bad thing about carbon buildup is the carbon can get hot enough to glow and cause preignition from the hot carbon setting of the fuel mixture.
Not to mention reducing displacement if the carbon is on the piston :lol:
OK, enough of this... I gotta get back to painting the house :sad:
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I run (for the first 1200Klms, cause thats all I've done so far) Caltex Vortex pulp, currently $1.32 per litre and falling, 1200 hasn't missed a beat since I got it :bigok:
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I run 87 in my Mazda, occasionally 89 if I can get it for not much more. It improves gas mileage -slightly-, but not enough to usually justify it's purchase. The car doesn't really run any better on 89. If I end up putting the Turbo on it, I'll have to run premium though. Not doing that until the warrenty expires, however, so no worries yet.
The Bandit, however, runs on Premium and only Premium! I ran 87 octane -once- and it pinged like crazy. 89 octane is doable, but it still pings under heavy load. 91 octane and she's smooth. :bigok:
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There are sooo many variables associated with this, it's not worth arguing. But, that said I run 87 in the bandit and 89 in the merkur(turbo) In the winter I have run 87 when the air charge temps are a little cooler, and this is with 18#'s of boost. It just depends on where you live, how you ride, etc.....
Josh
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I run my 05 B12 on 91 octane as recommended in the manual. It seems to run just fine. :grin:
Just as well to as here in the good old NZ the price of fuel is increasing weekly. :crybaby: :crybaby: :banghead:
At the moment we are paying $1.55 lt for 91 and over $1.60 lt for 96. Also one of the big companies is withdrawing 96 in favour of 98 octane. They are doing the hard sell and stating that it is a performance fuel and is reccommended for late model sedans and sports cars. Thats just great but at nearly $1.70 a liter they can keep it.
My wife thinks I should trade the B12 on a 50cc scooter :wink:
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The Bandit, however, runs on Premium and only Premium! I ran 87 octane -once- and it pinged like crazy. 89 octane is doable, but it still pings under heavy load. 91 octane and she's smooth. :bigok:
What's the compression ratio on the 400?
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I run my 05 B12 on 91 octane as recommended in the manual. It seems to run just fine.
Check your manual again... I'm sure it does not recommend 91 octane.
(Unless of course you use the RON octane measurement in NZ vs. the RM/2 method we use in the States.)
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What's the compression ratio on the 400?
11.8:1 I believe. I'm at work now, so I can't check the manual.
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The compression ratio on the 400 is much higher than the 1200, and therefore would require higher octane.
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even with an advancer, jet kit & slip-on, 87 is fine, even in 100 degree summers in Okla CIty...I use 86 in the mountains....the only time I ever had problems was in hot muggy traffic at Daytona and it was pinging pretty bad, I did switch to premium.....
The problem with what you say here is that "pinging" is usually only audible and problematic under heavy load/throttle. If you heard it in traffic at Daytona where you were presumably just cruising around I'd be pretty damn concerned! :shock:
Unless you have some phenomenal hearing, I have a hard time with anyone hearing pinging on a bike with a slip-on and wind noise to boot. I was barely able to hear it on my bike when it was still stock, and then only under the following conditions:
~warm weather
~3-4th gear
~full throttle roll on @ 2-4000rpm
~leaning off the bike with my ear near the valve cover
It always did it with regular of any brand and didn't with mid-grade of any brand. This was sufficient and there was no need to switch to premium.
Although many Bandits may run fine on regular, bikes vary and people's ability to pick up on issues like pinging vary even more.
A bike that was not broken in properly or has tons of miles on it may very well have .5:1 lower compression and that IMO is enough to prevent pinging on regular.
It was due to high traffic & high heat......was very severe. only occurance...bike does have advancer, etc.
I thought I was pretty clear. It was 2 1/2 years ago and the bike has another 15k miles (45k now)
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I run my 05 B12 on 91 octane as recommended in the manual. It seems to run just fine.
Check your manual again... I'm sure it does not recommend 91 octane.
(Unless of course you use the RON octane measurement in NZ vs. the RM/2 method we use in the States.)
My money is on NZ uses the RON method, like Europe and therefore the higher octane number than what's in the US version's owner's manual.
:motorsmile: :beers: :motorsmile:
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Guys, I've heard all the arguements for and against the use of premium v regular. And you can fire all the facts, or, so called facts, owners manuals, my mates a professor, my bike mechanic said, out the bloody window.
The cold hard facts are, if your bike pings when you use regular, ( and there is no other contributing factors ) change to premium. If your bike runs notiably better on premium keep using it.
If your bike runs just fine on regular, stick to it. Thats the end of the story.
Personally I have no choise but to run premium, the poor little B6 pings its little brains out on regular, ( And I can clearly hear it under load, I dont need to lean down and put my ear to the rocker cover) yet its fine on premium. No, my little B6 is not stock, Mid pipe, muffler, air box, carb mods, and advanced igniton timing. Compresson however is stock.
Next I will be reading how shell optimax, is crap. (Like I keep hearing here in Oz) Funny thing is some people here in oz bag the stuff big time, and state how they never, use nothing but BP ultimate cause its so much better........ Funny thing is, BP premium fuel plant has been offline, so what have they been selling unbeknown to most people, yep you guessed it, shell optimax. But I must admit I am a fan of the vortex product.
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I'm with you Mick. Use what you bike likes. The premium stuff makes no noticable difference for me, except it empties my wallet quicker. However, the Treasures M750 runs like shyte on anything but premium, and she agress the Vortex stuff is pretty good. She's tried the optimax once and the bike didn't seem 'right', but maybe it was just a bad tank full. We've got a couple of Kmart vouchers, so she'll probably fill up on the optimax this weekend, and see how it goes.
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Hey there PaulVS. I checked the manual again and it definately states 91 Octane. So does the sticker on the fuel tank. Not sure who RON is but bike runs great on the fuel I am using. I did not realise prior to this post what a huge spread there is when talking types and qualities of fuel. All I knew is how expensive it is becoming.
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Hey there PaulVS. I checked the manual again and it definately states 91 Octane. So does the sticker on the fuel tank. Not sure who RON is but bike runs great on the fuel I am using. I did not realise prior to this post what a huge spread there is when talking types and qualities of fuel. All I knew is how expensive it is becoming.
If N.Z. uses RON method... you're probably using the equivalent of 87/88 octane U.S.
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Hi Guys,
when I pick my bike my good mate told me only use feul that is 91% & higher well vortex prim is 95% & vortex Gold is 98% these are the only two I use I seem to get better km's from both & the bike runs great ( I now use vortex prim in my car & get about 80 kms more them regular feul) .
all the best matt :) your friend
Safe Ride :motorsmile:
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Couple of points that I wanted to add to the Octane discussion that I haven't seen in this thread yet.
I haven't heard my '03 B12S ping yet, but my older Yamaha XJ1100 would really ping at sea level in the summer on 87 octane.
1) Octane requirements are reduced by about 1 RON per 1000 feet of altitude. Besides the Yamaha I have an older Dodge Charger very sensitive to Octane. At sea level (especially in Summer) she needs 91. In Calgary at 3500ft 87 octane is OK. Another variable is that Vancouver has hills - Calgary really doesn't - so more of an opportunity to damage your engine in Vancouver over time.
2) Premium gasoline is manufactured in a refinery in a number of ways according to the age of the technology. Platforming is older, Continuous Catalytic Reforming is newer. Either way the plant "units" and processes involving platinum catalysts are extremely expensive - these units do not have a secondary purpose besides making higher octane. Premium gasoline typically has about 2% higher "energy density" than regular. Although really hard to measure this should equate to 2% better fuel mileage.
3) Premium gasolines are handled entirely separately once they leave the process unit which increases distribution costs. Most new service stations blend their 89 mid-grade through their pumps and only carry 87 and 91 octane in below ground wet storage.
4) Premium gasoline is not only about octane - Brand name oil companies typically fortify their premium products with additional chemical additive packages - almost always injected at the local truck loading rack. For instance Shell V-Power has twice the additive package that their Bronze gasoline does - as well as the higher octane.