higher octane gas in Ghost/X22R

[Jeshmont]

Is it acceptable to run higher octane? I know some engines higher octane can cause issues but I hear the Hawk seems to prefer it over regular and some like to avoid ethanol all together for obvious reasons. Thoughts?

[TxTaoRider]

Oh good, an octane post!
It wont help or hurt anything on a stock compression engine. I am not a fan of ethanol, but it's usually ok if it doesn't sit for a few weeks unused.

[Falkon45]

I've never used regular in any of my motorcycles. There's no real savings in it. I have gone from 93 to 100 octane with my rc390 and my MT-10. No noticable power gains in either bike. But, now that the Yamaha had been modded quite a bit, the power and torque curve have changed dramatically. Gonna try 100 in it again. It's expensive at 9.99 a gallon. Lol

Might try it on the Lifan for giggles. That plus a hotter spark plug might actually be noticable.

[Barnone]

There is no savings in using regular gasoline in a engine that will run fine with it versus using a more expensive fuel? Are you kidding me?

[Falkon45]

There is no savings in using regular gasoline in a engine that will run fine with it versus using a more expensive fuel? Are you kidding me?

The minute amount of fuel your using. A 3-4 gallon tank might save you a dollar or two. But you'll go to refill faster running regular than you will using premium. Savings is negligible. So no, I'm not kidding you. Now, there's a bigger difference when you're filling a 23 gallon truck. My fuel mileage is pretty much the same, and with my usual heavy foot, my gas mileage stays the same, regardless. That's about a $10 savings.

I'm not telling you this in theory. This has all been practiced.

[franque]

In fact, the opposite is true for an engine that isn't retarding timing to run on lower octane numbers. The higher the octane number, the less BTU/gallon, and therefore the less potential energy. You're literally pissing money down the drain if you're paying for higher octane in an engine that isn't designed to need it. Run the lowest octane you can without pinging, and your have the most efficient motor.

[TxTaoRider]

I love octane and oil threads.

Most gasoline powered cars and trucks made in the past 30 years use detonation sensors "knock sensors" that allow the ignition advance to become limited if it detects that the engine is "detonating" because of too low of octane (or a lean cylinder, or overheating,etc). So in those engines it is possible that running higher octane fuel will provide better mileage over a fuel with lower octane. But even then, it would only provide improvement if the lower octane fuel was too low and causing the spark to not advance completely.

All this usually has nothing to do with our low compression, conservative no knock sensor equipped spark advanced, stock bikes. You could see a difference if the bike was running way too lean, or way too hot, or the combustion chamber was carboned up, but then it's a band aid covering up an issue that needs to be fixed.

Can we talk about oils? I love this stuff.

[Falkon45]

In fact, the opposite is true for an engine that isn't retarding timing to run on lower octane numbers. The higher the octane number, the less BTU/gallon, and therefore the less potential energy. You're literally pissing money down the drain if you're paying for higher octane in an engine that isn't designed to need it. Run the lowest octane you can without pinging, and your have the most efficient motor.

Again, this is all practice. These are things I've done over the years of riding/driving. So, no, I'm not pissing away money, because I've been doing the experimenting....

I mean... I literally build engines for fun. I experiment with octanes because it interest me, and I like to see the results, good or bad. I've literally spent $150 on mediocre 100 octane fuel because it's readily available at a gas station here instead of going for MR12 race fuel to see if paying $10 a gallon pump gas is worth it for my 12.6:1 rc390, or if I could get better power and milage in my MT-10 during track days. Results on those. Even after the rapidbike and bigger injector on the rc390, no change. But, this may be due to the rapidbike being installed incorrectly by me, as my bike was actually slower than before. This was realized when I couldn't get away drag racing someone who was two-up on a cbr300. The MT-10, no noticable gain in power or efficiency. But, I've since had the ECU flashed and new full exhaust. Time to revisit that test.

There is a noticable change in the Lifan on the just due to temperature. In the cooler mornings I go to work, the bike actually struggles more than in the warmer afternoons I head home. And noticable difference is it takes everything it it has just to make 60 mph, and that's after running idle for 30 minutes to allow operating temps. That's at a 50° morning. The noon to evening temps are close to 80°. And after a 5 minute warm-up, the bike pulls to 65 unnoticed. I usually don't even realize I'm in 6th gear, because the bike just pulls like I'm still in 5th. And that's just from ambient temperature.

Reading results based on theory is one thing. Actually putting theory into practice is another. My results have proven your theory incorrect, and you still say I'm wrong.

[Jeshmont]

In the end...I messaged Venom Support who said they recommend 91 or 93 in their motorcycles although I’m sure that doesn’t quell the debate


Next up what’s the best oil to use? Lmao

[franque]

The numbers quoted by Chinese manufacturers/distributors are usually RON, which depending on the blend are 5-7 points higher than the octane measurement used in the US, which is (RON+MON)/2.

Unmodified modern engines running knock sensors and modern combustion chambers with FI, that are street legal, don't need higher than the available 91/93 (R+M/2)... They wouldn't sell them otherwise, the liability of a motor going boom isn't worth it to the manufacturers. Most will run fine on the cheap stuff, but if it's a higher performance motor, it might pull some timing to keep it safe. If your RC390 is still running the cat, it's a fortunate thing you didn't buy the MR12, that stuff is leaded and will destroy a cat in no time.

I'm not certain what you're trying to explain with your Chinese bike, it's lacking detail so I'm not sure what you're getting at.

The cheap air-cooled bikes are usually running around 9:1 compression on mild cams, so unless you're winding your way up a hill in first gear at 110° out, donation is not an issue. Higher octane just lets you run more timing without detonation, or prevents detonation in a motor that is prone to it.

Theoretically you could lean the motor out a little bit on higher octane, but what's the point? They're cheap bikes that run on cheap gas, no sense in spending a significant value of the machine on each fill up with $10/gal gas. If it floats your boat, go ahead, but it's doesn't change the fact that you're still spending more than 3x what's necessary on fuel, there's also probably more than a little confirmation bias (i.e. expectations of better performance with no actual change) when you're doing/buying/using something that's 'premium'; there's plenty of Psychological studies about that.

[Falkon45]

I have no air cooled bikes. All mine are liquid cooled. All my bikes are decayed. My only stock vehicle is my 2017 f150 Ecoboost. Most manufacturers will recommend premium if they have a compression higher than 9.5:1 and they aren't direct injection.

Cooler temperatures actually make my kmp200 run worse than warmer temperatures. It's backwards from most vehicles.

And, this is about 15 years or so of experimenting with ALL my vehicles. So, I doubt I need any psychological evaluations on the subject.

[JerryHawk250]

Ethanol free 87 octane is all you need for the Ghost. No gain with 91 octane fuel.