Fuel Used

[BCT748]

I take back every mean thing I said to you in your introductory thread...well played sir...

Run the good stuff- 91/93 only in my baby.

I don't even remember what was said in my intro thread. Did you even say anything in it or are you just trying to get on my good side so you can ask me into a private chat?

[RandyO]

get a fucking clue all you fucking idiots


there is no such thing as "cheap stuff" it's all expensive

nor is there a such thing as good stuff here in the US, it's all the same fucking garbage with additives to control the combustion rate

in europe, premium actually does have a higher energy content

if your OM calls for premium, (many bikes do) then use it otherwise your $2/fillup that you don't give a shit about just tells me that your fucking stupid when it comes to spending your money, and that's ok with me

[Cheese]

I use 87 but I only have a 4.5 gallon tank so about 20% of what I get at the pump is whatever the person before me left in the hose.

[ZX-12R]

I use 87 but I only have a 4.5 gallon tank so about 20% of what I get at the pump is whatever the person before me left in the hose.

I keep my eyes open for these:

[Kham]

America and Canada use a different way to measure octane than most of the rest of the world. We use an average between the research octane number and motor octane number. Most of the rest of the world just uses the octane number to determine the octane of fuel. The motor octane number is a rating of how the fuel reacts under load so it is a little more accurate.

Why are you even thinking about using 87 in your bike? The price difference isn't that much when you do the math out. Lets say it costs an extra 40 cents per gallon for 93 and you have a 5 gallon tank. You are only going to be spending an extra $2.00 per fill up. lets say you ride from April to September and you fill up once a week. That means you will fill up your bike 26 times and will cost you a whopping $52.00 more than if you used 87. I think I would rather spend the extra 52 bucks a year rather than worry about jumping time or breaking something in my motor.

lets say you fill up twice a week. that would be $104.


anyway how do you tell if engine is pinging? cause i can't.

i remember some douche said, for a high octane engine, once in a while fill up with low octane and take it real easy. it'll clean up the crap left by high octane. oh sorry honclif.

[Brian675]

America and Canada use a different way to measure octane than most of the rest of the world. We use an average between the research octane number and motor octane number. Most of the rest of the world just uses the octane number to determine the octane of fuel. The motor octane number is a rating of how the fuel reacts under load so it is a little more accurate.

Why are you even thinking about using 87 in your bike? The price difference isn't that much when you do the math out. Lets say it costs an extra 40 cents per gallon for 93 and you have a 5 gallon tank. You are only going to be spending an extra $2.00 per fill up. lets say you ride from April to September and you fill up once a week. That means you will fill up your bike 26 times and will cost you a whopping $52.00 more than if you used 87. I think I would rather spend the extra 52 bucks a year rather than worry about jumping time or breaking something in my motor.

+1 Even if you ride like the wind your probably still getting better mpg than most cars and trucks.

[SprintPoser]

I run the mid-grade in my Triumph because that's what the manual says to run.

On my car(s), BMW says to run "91K Premium" and there's a lot of debate about what that translates to in the R+M/2 method of octane rating. So a test was in order. I ran through 2 tanks of the mid-grade and got an average of 24.5 MPG. With the 91/93 premium, that went to 25.5 MPG. I thought it was cheaper to run mid-grade, but even with a ten-cent difference in price, the math proved it was cheaper to run premium.

My bike gets similar results. I get about 210 miles out of a tank of regular 87 before the low fuel light hits, but 230 miles with mid-grade. On my bike, I just like to have more range. I notice no difference in performance.

[taxonomy]

Octane, I believe, is how tight the molecules are bound together. This controls how fast the flame front can tear them apart. Proper rate of expansion of the flame front would, in effect, relate to timing.

It is my understanding that some engines have knock sensors and can advance or retard timing to properly position spark relative to TDC. In an advanced engine with real "3D" ignition mapping and a TPS and O2 sensor some advantage could be gained in efficiency either as it relates to MPG or power output with higher octane.

So, there are circumstances where higher octane will return better results both in performance or mileage (which is a kind of performance) but only in engines designed to take advantage of this.

It is also my understanding that it may be worth it to run higher octane in situations where there is very high ambient temperatures or the engine is being run near it service limits, e.g. at very high RPM.

In either case you'd wind up with high temperature in the combustion chamber and increasing the octane could reduce the possibility of detonation. Conversely an engine may perform better with lower octane when run cold, say running a car engine on many short trips in the winter.

In no case will an engine not equipped with knock sensors perform better when run with higher octane within its service limits.