What octane fuel you using?

[Deanohh_imp]

There is no knock sensor.

[_imp]

I read in the Aussie manual that 91 was required, so that is why I was using it. Then read in the US manual 86+ was OK.

Funny but the FZ8 also is fine on 87 according to the manual.

Aussie might be one of the countries that use a different scale for their gas numbers.

Aussie might be one of the countries that use a different scale for their gas numbers.
They do, they use the European system of octane rating. Their 91 is our 87. Using a higher octane fuel than is required for a stock engine will do absolutely nothing for you besides cost more money. As mentioned, if you want to pay more, find 100% gasoline and use that, you will actually get better performance that way (only about 3-4%, but it's also better for the engine). If your fuel says "may contain up to 10% ethanol", you can bet it has 10% ethanol in it.

This is one of those internet arguments that happens constantly and consistently, with everyone going round and round on it.

Aussie might be one of the countries that use a different scale for their gas numbers.
They do, they use the European system of octane rating. Their 91 is our 87. Using a higher octane fuel than is required for a stock engine will do absolutely nothing for you besides cost more money. As mentioned, if you want to pay more, find 100% gasoline and use that, you will actually get better performance that way (only about 3-4%, but it's also better for the engine). If your fuel says "may contain up to 10% ethanol", you can bet it has 10% ethanol in it.

This is one of those internet arguments that happens constantly and consistently, with everyone going round and round on it. This is exactly correct with respect to the Aussie/UK octane rating but not entirely accurate with respect to being able to get more out of the higher octane. Some engines have built-in knock sensors and can automatically adjust ignition timing to take advantage of the higher rating. My FJ Cruiser is one of them but there are many others. The documentation from Toyota specifies this. Since Honda didn't tell us about the speed limiter it's possible that other features are built in that we wouldn't know about either.

Aussie might be one of the countries that use a different scale for their gas numbers.
They do, they use the European system of octane rating. Their 91 is our 87. Using a higher octane fuel than is required for a stock engine will do absolutely nothing for you besides cost more money. As mentioned, if you want to pay more, find 100% gasoline and use that, you will actually get better performance that way (only about 3-4%, but it's also better for the engine). If your fuel says "may contain up to 10% ethanol", you can bet it has 10% ethanol in it.

This is one of those internet arguments that happens constantly and consistently, with everyone going round and round on it. This is exactly correct with respect to the Aussie/UK octane rating but not entirely accurate with respect to being able to get more out of the higher octane. Some engines have built-in knock sensors and can automatically adjust ignition timing to take advantage of the higher rating. My FJ Cruiser is one of them but there are many others. The documentation from Toyota specifies this. Since Honda didn't tell us about the speed limiter it's possible that other features are built in that we wouldn't know about either.
That's not how the knock sensor works... your FJ Cruiser engine is designed for 91 octane and that's when you get the most power. The anti-knock sensor *lets* you use lower octane. You aren't unlocking "hidden" power by using higher octane gas, you're just using what you're supposed to be.

Here's the test: Go and get race fuel, then have it dyno'd.

I am willing to bet that it will *not* increase your horsepower. I will make this offer to anyone here in the South, actually: If you go and do 3 runs using 87, 91, and 95+ octane fuel with a stock vehicle, I will meet you for the runs. If the dyno shows a larger increase than standard margin of error on race fuel, I will pay for the runs and buy you a 12-pack. If it doesn't, you pay for the runs and a 12-pack.

Using higher octane gas than your engine is DESIGNED TO USE, will not gain you a single thing but a higher bill at the pump.

I don't think anybody has disagreed with this. I'm an automobile dealer of 25 years and have sat through countless training courses having the latest and greatest new tech explained to us by factory reps. I'll use some examples. The Chevrolet Silverado is designed to use 87 octane gas and it has knock sensors that can retard ignition timing. On a dyno it will not produce more power if you put 91 octane in it. The Toyota FJ Cruser is designed to run on 87 or 91. It also has knock sensors that retard and advance ignition timing. The FJ will produce more horsepower on 91 octane than it will on 87 octane because it will advance ignition timing to the threshhold of detonation. I don't know how far their system will keep going and if it would make more power with 110 octain race fuel but it's possible.

One of my hobbies is racing the standing mile in my Ford GT and I've spent a ton of time on the dyno with a laptop messing with ignition advance, boost, and air/fuel ratios. It's easy to see how power rises and falls with changes in ignition advance alone and the objective is to advance it as far as possible without causing detonation. On 91 octane pump gas my GT puts 865 HP to the rear wheels, with the 93 octane fuel available in many parts of the country my GT can run a couple more points of ignition advance and then it puts down 910 HP. The GT has no knock sensors and ignition advance is not automatic so I have to change it with a handheld tuner but in other cars like the FJ it's done constantly and automatically.

For a real ride, on race day, I run 116 octane VP leaded race fuel (about $28 a gallon) and my twin turbo Heffner Ford GT put 1146 HP to the rear wheels. From a standing start at the Texas Mile it accelerated from 0 to 221mph in 26 seconds. The higher octane allows both more boost and more pre ignition advance.

In short and to get back to the point, some new cars have very high compression and so they rely upon their engine electronics to retard ignition timing to prevent detonation. They will make more HP on a dyno using 91 than they will with 87. Some other cars don't have such systems and assuming they don't detonate on 87 octane, they won't make any more power with 91 or 93.

A couple things are absolute however. 1. Changing ignition advance changes horsepower, whether it's changed automatically by the car itself or by the owner using a tuner. 2. Octane is a measure of a fuels resistance to detonation (it is not a measure of energy or power) and if an engine has both higher octane fuel AND the ability to change it's operating parameters to take advantage of the additional resistance to detonation, it will make more power on higher octane gasoline.

I can almost guarantee you that none of this applies to the CB1100 because I'm pretty certain it doesn't have knock sensors. Cheers.

Chip

I don't think anybody has disagreed with this. I'm an automobile dealer of 25 years and have sat through countless training courses having the latest and greatest new tech explained to us by factory reps. I'll use some examples. The Chevrolet Silverado is designed to use 87 octane gas and it has knock sensors that can retard ignition timing. On a dyno it will not produce more power if you put 91 octane in it. The Toyota FJ Cruser is designed to run on 87 or 91. It also has knock sensors that retard and advance ignition timing. The FJ will produce more horsepower on 91 octane than it will on 87 octane because it will advance ignition timing to the threshhold of detonation. I don't know how far their system will keep going and if it would make more power with 110 octain race fuel but it's possible.

One of my hobbies is racing the standing mile in my Ford GT and I've spent a ton of time on the dyno with a laptop messing with ignition advance, boost, and air/fuel ratios. It's easy to see how power rises and falls with changes in ignition advance alone and the objective is to advance it as far as possible without causing detonation. On 91 octane pump gas my GT puts 865 HP to the rear wheels, with the 93 octane fuel available in many parts of the country my GT can run a couple more points of ignition advance and then it puts down 910 HP. The GT has no knock sensors and ignition advance is not automatic so I have to change it with a handheld tuner but in other cars like the FJ it's done constantly and automatically.

For a real ride, on race day, I run 116 octane VP leaded race fuel (about $28 a gallon) and my twin turbo Heffner Ford GT put 1146 HP to the rear wheels. From a standing start at the Texas Mile it accelerated from 0 to 221mph in 26 seconds. The higher octane allows both more boost and more pre ignition advance.

In short and to get back to the point, some new cars have very high compression and so they rely upon their engine electronics to retard ignition timing to prevent detonation. They will make more HP on a dyno using 91 than they will with 87. Some other cars don't have such systems and assuming they don't detonate on 87 octane, they won't make any more power with 91 or 93.

A couple things are absolute however. 1. Changing ignition advance changes horsepower, whether it's changed automatically by the car itself or by the owner using a tuner. 2. Octane is a measure of a fuels resistance to detonation (it is not a measure of energy or power) and if an engine has both higher octane fuel AND the ability to change it's operating parameters to take advantage of the additional resistance to detonation, it will make more power on higher octane gasoline.

I can almost guarantee you that none of this applies to the CB1100 because I'm pretty certain it doesn't have knock sensors. Cheers.

Chip +1
If a vehicle's computer can adjust ignition timing relative to octane/knock, then you get more power. Does the CB have it? Don't know but even if improbable, it's not impossible. Does seem more likely for an air-cooled engine which is more prone to hot spots in the combustion chamber on warm or hot days.

There is no knock sensor.

But how do you know this?

[Deanohh_imp]

I have thoroughly examined every circuit in the wiring diagram, read every word in the service manual, reviewed every photo of engine assembly and disassembly, searched the cylinder block for a little microphone, received a message from God, and on top of that I know everything. Now you prove to me that it has one.

[Yoyodyne_imp]

From Bell Laboratories:

Ethanol in Premium Gas?

There is a difference between states on whether premium gas specifically has ethanol in it or not. Or, more correctly, whether it's required to have it in it. Two states in the Union, Missouri and Montana, have specific exemption to allow ethanol-free premium gasoline. So if you live in one of those two states, you can be thankful.

For the rest of us, we are faced with the unpleasant reality that the refineries are all but tied into putting ethanol in premium gas. This is because they have to use the ethanol to raise the octane level of their gasoline blend in order to satisfy the higher octane requirements of premium. This is one reason why you don't get better gas mileage with premium gas, because an essential part of that blend is a component that has less energy and forces the gas mileage down simply by nature.

So don't get fooled into thinking you can escape ethanol's grasp simply by paying more and getting premium gas.

I don't claim that all premium gas is ethnanol-free, I'm sure that varies by where you live. In my region of Wisconsin, Shell V Power (premium) is clearly marked on the pump as 100% gasoline with no ethanol added. YMMV and all that...

[the Ferret]

From Bell Laboratories:

Ethanol in Premium Gas?

There is a difference between states on whether premium gas specifically has ethanol in it or not. Or, more correctly, whether it's required to have it in it. Two states in the Union, Missouri and Montana, have specific exemption to allow ethanol-free premium gasoline. So if you live in one of those two states, you can be thankful.

For the rest of us, we are faced with the unpleasant reality that the refineries are all but tied into putting ethanol in premium gas. This is because they have to use the ethanol to raise the octane level of their gasoline blend in order to satisfy the higher octane requirements of premium. This is one reason why you don't get better gas mileage with premium gas, because an essential part of that blend is a component that has less energy and forces the gas mileage down simply by nature.

So don't get fooled into thinking you can escape ethanol's grasp simply by paying more and getting premium gas.

I don't claim that all premium gas is ethnanol-free, I'm sure that varies by where you live. In my region of Wisconsin, Shell V Power (premium) is clearly marked on the pump as 100% gasoline with no ethanol added. YMMV and all that...

I don't claim that all premium gas is ethnanol-free, I'm sure that varies by where you live. In my region of Wisconsin, Shell V Power (premium) is clearly marked on the pump as 100% gasoline with no ethanol added. YMMV and all that...

Yea thosevweren't my words, I just down loaded it from the company's website.

When I was in Minnesota a few weeks ago I was filling up at a gas station which was premium and 10 % ethanol for like $ 4.28 gal and a guy on a Harley and pulls up to a pump way in the back. Solo pump. When I went in to pay I asked why the guy was filling up back there and station attendant said he was filling up with non- oxygenated gas for $4.89 a gal. Normally used in mowers and boats he said.

[Flashman_imp]

I just take my CB1100 down to the fuel dock at the marina a half mile from my house and fill it with Valtech ethanol free marine gas. The fuel dock is just off the parking lot.

It's 87 octane and already has Stabil mixed in. They are not supposed to put off road fuel into on-road vehicles but I just tell them with a wink and a nod that I'm going to siphon the gas into my Honda outboard on my dingy, which I have actually done on a few occasions.

Buying 1,000 gallons of diesel a year from them for my boat probably helps.

A lot of marinas sell ethanol free gas.

Mike

[ChipBeck_imp]

Here in AZ there is no escape from ethanol. 10% in all three grades of Shell, Chevron, Arco, you name it. When I'm in Colorado I can often find ethanol free premium and that's what I buy when it's available. Each state has it's own rules as to what fuel blends must be sold. And while ethanol does raise octane, that's not why it's put into gasoline. Regular gas and Premium gas are both 10% ethanol here. It is put into our fuel to lessen our dependence upon foreign oil. It doesn't work in practice because for every gallon of low energy, water absorbing, corrosive ethanol we produce, a gallon of high energy efficent oil based diesel and over 100 gallons of water are consumed farming and transporting that swill. But the "intent" is reduce our dependence and that's all that matters these days.

Chip

[SUPERCRUZ_imp]

Running 91 Octane in my CB. Here is my theory. I am not looking for extra power but guarding against pre-detonation on hot days. Lower octane fuel burns quicker and is more pre disposed to pre-detonation in high compression engines. While the CB1100 does not have all that high a compression ratio, it is air cooled and thus in my opinion subject to higher than normal head temperatures. It would seem logical to me that running higher octane fuel such as 91 will combat any chances for pre detonation of the fuel on an air cooled engine such as the CB. For those running 87 in their CBs, this is what the manual calls for and thus I am sure it is just fine. I choose to run the 91 for peace of mind and have not had any issues thus far. On a side note, I also run a half ounce of StarTron fuel enzyme in each tank of gas. This stabilizes the fuel and helps with keeping the injectors clean and removal of water build up in the tank.

[wildezt_imp]

Shell V Power.

[Guth_imp]

For those so inclined, I believe there are a few various sites out there such as this one:

[url=http://pure-gas.org/index.jsp]Pure Gas