which kind of gas?

teslas

teslas

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I'm running through my first tank of gas and I'm already down 4 bars at about 105 miles. Is this normal? I put Chevron Supreme with 91 Octane. I was down one bar at only 31 miles.

Is this normal? Am I putting in the right Octane of Gas? What are you guys on this side of the pond all using?
 
teslas said:
I'm running through my first tank of gas and I'm already down 4 bars at about 105 miles. Is this normal? I put Chevron Supreme with 91 Octane. I was down one bar at only 31 miles.

Is this normal? Am I putting in the right Octane of Gas? What are you guys on this side of the pond all using?
Click to expand...

I'm usually between 45 and 60 miles on the first bar. I typically run between 185 and 205 on a tank about the time the tach switches over to odometer. The bike will do better when it gets loosened up. I run 93 octane.
 
The FZ6 doesn't have a knock sensor, so it won't take proper advantage of high octane gas by advancing the timing. I just run regular in mine and it doesn't complain. Gas mileage is about 38mpg (still on the breakin)

Fred
 
THis is very strange indeed. I wonder if my fuel sensor is all wacked out?
I"ve never seen 93 octane in the states.

Maybe I only need 89 Octane? What do the rest of you guys use?
thanks
 
I used 91 until I tried 87 it made no difference other then the price. if you look in the owners manual 87 is all that recommended, your mileage will very depending on your riding style I've gotten everywhere from 36 MPG to 55 MPG it just depends on how aggressive your riding.
 
During breakin I do not ride aggressive at all, but I just take it real easy.

On another note can someone explain the difference between "Pump Octane" and Research Octane is? I've NEVER understood it.

THis is from page 3-11 in the 07 user manual.

Your Yamaha engine has been designed
to use regular unleaded gasoline
with a pump octane number
[(R+M)/2] of 86 or higher, or a research
octane number of 91 or higher.
 
teslas said:
THis is very strange indeed. I wonder if my fuel sensor is all wacked out?
I"ve never seen 93 octane in the states.

Maybe I only need 89 Octane? What do the rest of you guys use?
thanks
Click to expand...

+1 Exactly, where do you guys tank up? 91 is pretty much the highest standard at the gas stations. Are you using airplane fuel? LOL
 
teslas said:
Your Yamaha engine has been designed
to use regular unleaded gasoline
with a pump octane number
[(R+M)/2] of 86 or higher, or a research
octane number of 91 or higher.
Click to expand...

R is for the Research Octane rating.
M is for the Motor Octane rating.
These are two methods of measuring octane. What's on the pump is usually (R+M)/2 which is the average of the two.

Octane is just resistance to detonation. Higher octane fuels have more xylene or toluene in them, both of which have extremely high octane ratings (117 and 114 if I remember right).

(As a sidenote, I tested out a gallon of xylene mixed into four gallons of 89 octane gas. The result performed like premium in my turbo bike, which does normally detonate on 89 octane fuel. I never tried a gallon into 91 or 93 octane, but the results would have been fun.)

Due to this detonation resistance, you can advance the timing, or increase the engine's compression ratio, or add a blower (another way to increase compression ratio) and not have the engine detonate.

The thing is, lower octane fuel actually produces more heat than high octane, which means more energy. So if you haven't got a knock sensor, racing engine or blower, the lower octane fuel can make more power than the premium stuff. The only way the high octane fuel makes more power is if you retune to take advantage of it.

Fred
 
Wikipedia has a good article about octane ratings.
Octane rating - Wikipedia, the free encyclopedia

Note that the Research Octane rating of a fuel is usually 8-10 points higher than the motor number. So if you are buying 89 octane fuel than the Research rating is probably around 94, and the Motor octane is going to be around 84.

84 + 94 / 2 = 89

Given Teslas' info "[(R+M)/2] of 86 or higher, or a research
octane number of 91 or higher." we can see that 89 octane fuel is just fine for the bike no matter how the octane at the pump is calculated.
 
So this may be the reason why I am seeing such poor gas mileage? I am not getting the detonation and thus burning more fuel to get the same amount of power as a lower Octane?
Next tank will be 89.
 
To clarify, detonation is bad. It's what blows holes in pistons and destroys engines if allowed to continue. Normally the gas burns in your engine as a fire. A very fast fire, but still a fire. Detonation is an explosion, and the associated shock waves do bad things (too much detail to go into, just accept that explosions are bad :) )

I'd recommend just resetting your trip odometer when you fill up and then at the next gas stop, calculating your mileage. I don't think you have anything wrong with your bike. At most, your fuel gauge reads a little differently from those of other posters. That's not at all uncommon, and I wouldn't worry about it until you've verified your fuel consumption via math.

Fred
 
There has also been threads on how far you can go on one tank, how far you can go on reserve, etc.....I would say the fuel topic has been beat to death.
 
Fred said:
The thing is, lower octane fuel actually produces more heat than high octane, which means more energy. So if you haven't got a knock sensor, racing engine or blower, the lower octane fuel can make more power than the premium stuff. The only way the high octane fuel makes more power is if you retune to take advantage of it.Fred
Click to expand...

Correct, the lower octane fuel does produce more BTU however, it also has a burn rate that is much faster. Here I can get fuel at a gas station that is up to 110 octane (6.00 per gallon.) My 1200 Sporty is designed to run on 87 octane from the factory however, if the temperature gets above about 85 ambient I wouldn't go near 87 octane as the engine temperature rises significantly and the bike generally runs like crap.

The biggest advantage in using premium fuel is it allows for the alteration of a run profile thus tweaking a few more horsepower out of the engine. This does not however mean you will lose horsepower by running it do to a loss of BTU as that premium fuel burn rate is slower thus being a longer burn when fired. You may also find the plugs last longer running premium.

One thing is for certain, if there is a perceived loss of power by running premium in a bike that should have regular, I would be very interested in seeing a dyno run on that bike. My money is on no loss or relative gains in horsepower that can be attributed to fuel.
 
on break in i have experienced lower fuel economy as well, on my wifes bike she was averaging 28 miles a gallon for the first 2000 or so miles and after that it started to climb steadily and is now around 58 MPG with the same riding style.

My FZ got me about 140 miles on the first full tank and I am hoping the phenomenon repeats itself and i get over 200 per tank.
 
teslas said:
THis is very strange indeed. I wonder if my fuel sensor is all wacked out?
I"ve never seen 93 octane in the states.

Maybe I only need 89 Octane? What do the rest of you guys use?
thanks
Click to expand...

nimzotech said:
+1 Exactly, where do you guys tank up? 91 is pretty much the highest standard at the gas stations. Are you using airplane fuel? LOL
Click to expand...

The standard Octanes here in WI are 87, 89, 93, all are R+M/2. I have seen these through out most of the Midwest. Elevation also plays in to what is available locally. I plan on running 89, no need for 93 with a liquid cooled bike, it usually is not that hot here (not much over 90 F) in summer anyway.
 
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