GULL 99 octane with 10% ethanol

[slopster]

It's probably in your head. Ethanol produces much less energy when burned then petrol. Some race cars use ethanol as a fuel because it allows a higher compression ratio to be used (and therefore more power) but need to have enormous carb jets to run properly which would be shocking for fuel economy. If your bike is running too rich on petrol I guess you could see an improvement but I don't think 10% ethanol would make much difference.

[Fooman]

It's probably in your head. Ethanol produces much less energy when burned then petrol. Some race cars use ethanol as a fuel because it allows a higher compression ratio to be used (and therefore more power) but need to have enormous carb jets to run properly which would be shocking for fuel economy. If your bike is running too rich on petrol I guess you could see an improvement but I don't think 10% ethanol would make much difference.

Ethanol has a lower calorific content (27 MJ/kg) than petrol (43 MJ/kg) but as it runs richer (stoichiometric ratio with air is 9:1) than petrol (stoichiometric ratio with air is 14.7:1), the total energy output is actual similar for equal units of air/fuel mixture (i.e. what actually gets burnt in the motor) - 3 MJ/kg for ethanol /air versus 2.925 MJ/kg for petrol/air.

For a 10% ethanol mix, the energy per unit air/fuel mix is 2.933 MJ/kg, or a difference of approximately 5/5ths of fuck-all.

Any noticeable power improvement may be down to improved combustion and or intelligent ignition timing taking advantage of the higher octane rating.

Ethanol also runs cooler as it has a latent heat of vaporisation higher than petrol (900 kJ/kg vs 400-500 kJ/kg)

What it actually means, for the same power output, you'll need a bigger fuel tank, as Ethanol is only slightly denser than petrol (0.79 vs 0.76), for the same range.

All numbers from Bosch Automotive Handbook, 3rd Ed.

Cheers,
FM

[Tumbles]

Excellent info here. I guess this means the first post could be running too rich and needs a tune?

[The Joka]

Well I agree with ya..

I had to throw $10 of the tree hugger juice in mine and I noticed a big difference straight away

[Mikkel]

All numbers from Bosch Automotive Handbook, 3rd Ed.

Cheers,
FM

I like this man!

[barty5]

correct me if im wrong i was told ( cant remember who) that produces less power therefore the cars that can use ie:my ssv-ve self addjust to use more fuel to get same amount of power. so therefore you would get less milage per tank cause your usin more more to get the same get up and go the stuff isnot that much cheaper than straight petrol so why bother (dont get all green peace either thats not me other wise i wouldnt drive a v8)

[Askelon]

I used it for a tank.. Hated the constant stink of the crap so went back to regular 95.. It also seemed to give me less km's than regular fuel.. From memory I got about 280k on a tank as opposed to the regular 300..

[discotex]

I was worried about the "problems with your fuel system may not be covered under warranty" line in the manual.

Rang Blue Wing and they said it would be fine (as the US is all 10% blend now anyway) but I could invalidate the warranty on fuel system parts if they were found to be corroded.

Because it's something new the car/bike companies are covering their arses in case there's a flood of fuel system issues.

If I'm going past Gull I'll fill up with it but it's nothing special. Just cheaper than BP and Mobil 98.

[Ulyssian]

Well I reckon I have more power since using it, that's all that matters. If I run it on shitty 91 all I get is spark knock, 95's to expensive and not much better than 91. So It's 99 Gull for this biker. Thanks for all your input interesting reading.

The Joker running on Urine and can wheelie for thousands of miles is not a bad one. You must have been drinking rocket fuel mate ha ha good yarn though.

[menee]

My local Gull, won't let me fill then pay when on my bike, even when I remove my gloves and helmet. I have to prepay, I don't mind doing this but they let cars pre-fill around me!!!, and don't get me started on my wahine filling up her late model Subaru, they wouldn't let her pre-fill either, she pulls up at pump and it doesn't work so she moves to another pump, and that doesn't work either, she goes inside and gets told that it is prepay only, she pays, and then goes back outside and another chick is filling up at the first pump, wifey says that it is on prepay but the chick says it's working fine !!! she gets pre-fill and several others had called in and were getting pre-fill around her, the only apparent difference that we could detect is that wifey is brown skinned!!

[barty5]

My local Gull, won't let me fill then pay when on my bike, even when I remove my gloves and helmet. I have to prepay, I don't mind doing this but they let cars pre-fill around me!!!, and don't get me started on my wahine filling up her late model Subaru, they wouldn't let her pre-fill either, she pulls up at pump and it doesn't work so she moves to another pump, and that doesn't work either, she goes inside and gets told that it is prepay only, she pays, and then goes back outside and another chick is filling up at the first pump, wifey says that it is on prepay but the chick says it's working fine !!! she gets pre-fill and several others had called in and were getting pre-fill around her, the only apparent difference that we could detect is that wifey is brown skinned!!

no it will be the boy racer style car in their eyes they suspect that all evo and subbie drivers and other like wise car owner will do drive offs.

[Grub]

Answer is Yes. I've just completed 20,000k in 9 months on the CBR (carbed) with this result ...
- 61.4% of the time it has run on 95 octane, 38.6% on 98.
- Using 98 where available and paying BP's outrageous prices for Ultimate98 or Mobil's 97.5, I have saved $16.33 over the 9 months ($21.78p.a.) due to more efficient combustion.

The additional benefits of greater acceleration, better running and cleaner burning then are the icing on the cake. I was told this very early in my return to riding by a guy we bumped into outside the Pauatahanui Cafe. I didn't believe him. That's partly the reason I started to keep a fuel log. He was right.