GZ250 Gas Mileage

[Newbiker08]

My question " Everyone is posting their mpg and thier average driving speeds, but what octane are people running?" I have talked with a few people one being the former owner of my bike. and I believe I have found something;

Higher octane= less fuel economy, higher preformance
Lower Octane= higher fuel economy, lower performance.

I have been able to run the 250 "stock" at speeds of 70-75 with some throttle left. but so far my average fuel consumption has been about 60mpg. 93octane
He was only able to run the bike at speeds of 65-70 and that was with a tail wind. But he averaged 70+mpg. 89octane.

I just wondered if some of the people getting the best milages are running a lower octane, and if people running higher octane are the ones getting lower mpg?

[Easy Rider]

Originally Posted by twigginton

My question is , if I lost 20 to 30 pounds, which I need to do anyway would I see much of an improvement in my top end speed?

Also, what about the 10% ethanol that is in all the gas nowdays, could that be causing a reduction in MPG? :??:

If you don't have a windshield and the 30 lb. loss results in less wind resistance the maybe a tiny bit.

Ethanol has about 85% of the energy of gas so with a 10% mix you would lose 85% of 10% or about 1 mpg.....if I did the math right.

[Easy Rider]

Originally Posted by Newbiker08

I have found something;

Higher octane= less fuel economy, higher preformance
Lower Octane= higher fuel economy, lower performance.

Sorry but in a "stock" low compression engine like the GZ, it just doesn't work that way.
I know you may have some experience that tends to "prove" it but the result likely is either the "placebo effect" or just a fluke of a small sample size (not enough data to really prove anything).

There also may have been differences in the gas other than the octane rating.......like slightly more ethanol in some of it.

Putting high octane gas in an engine like a GZ is just a waste of money........unless it just makes you feel better......which is priceless!

[Sarris]

Originally Posted by Sarris

My 2005 Owners Manual states 87 octane on page #7. Octane is an additive that decreases volatility in high compression motors to negate ping (pre-combustion). The higher the number, the lower the volatility. You can spend more on higher octane, but the truth is your GZ is third world transportation that will probably run on lamp oil, hooch, saki, dog shit, etc.

This is my statement from a previous post, and the info comes from the American Petroleum institute. Don't waste your money unless it makes you feel better, 'cause your GZ won't know the difference.

[5th_bike]

Originally Posted by happyhobo

Help this poor Canadian gal....how does this all work out at kilometers per liter?????

Here is a little table:
MPG-Km/L
60 - 25.5
62 - 26.4
64 - 27.2
66 - 28.1
68 - 28.9
70 - 29.8
72 - 30.6
74 - 31.5
76 - 32.3
78 - 33.2
80 - 34.0
82 - 34.9
84 - 35.7
86 - 36.6
88 - 37.4
90 - 38.3
92 - 39.1
94 - 40.0
96 - 40.8

Hm, I consistently get more than 30 kilometers per liter. Nice.

[jonathan180iq]

These numbers are a result of 21 tanks of gas and a year and a half: (Between Jan. 2007 and Aug 2008)

Avg. MPG: 66.96091

Avg. cost of gasoline: $3.05

Avg. Miles per tank: 179.4545

Avg. gallons per fill-up: 2.681818

[Newbiker08]

Originally Posted by Sarris

This is my statement from a previous post, and the info comes from the American Petroleum institute. Don't waste your money unless it makes you feel better, 'cause your GZ won't know the difference.

So if I run lower octane without engine knock, just go with it. OK sounds good to me. I have been running the 93 octane only because the copy of the owners manual from this site said 91 octane or higher. I never got the owners manual for my bike :sad: . So if your '05 manual says 87 I'll drop it down and see what happens. Although the 50-75 cents more to fill up the tank with premium is hardly noticable. Not like the 24gallon tank on my cage.

[Easy Rider]

Originally Posted by Newbiker08

So if I run lower octane without engine knock, just go with it. OK sounds good to me. I have been running the 93 octane only because the copy of the owners manual from this site said 91 octane or higher.

Ah HA! That online manual might be the cause of confusion for more than one person. It is, apparently, a European version, where they measure Octane differently. Wonder if anybody here has Adobe and could make a correction??

As for hearing engine knock, good luck with that. These bikes are known as "thumpers" for a reason !!

[philbert]

My GZ has been getting exceptional mileage. I bought this demo (training) bike with 534 miles on it back in mid-July. There are 1400 miles on it now. My MPG has been: 73 on the first fill-up, 75 on the next, 83 on the third, and 79 on the last one. Since I use the bike primarily for commuting I'm really happy with this 77.5 MPG average. It sure beats my cage mileage!

[philbert]

I've used 87 Octane with all but one of my fill-ups in which I used 89. I had a lot more engine knock (or perhaps pinging) with the 89 so That's why I'm sticking with the 87. Haven't considered trying the 91 Octane, I just don't see the point.