Shitty Petrol???

[Jinx3d]

hold fire guys. Avgas or 100ish octane is according to your theoery basicly the same as 91 with octane boosters now that dont sound right to me

I worked at an aerodrome for a while and was reading a tech manual and thats pretty much what it said.

Av gas = shit loads of lead. I dont think it has to be this way, its just cheaper to add lead. This was in the days of lead, not sure about now.
What you can say about av gas is that it is Slower burning. Perhaps this could be felt subjectively as a smooth running motor. Maybe?

Also, I agree that petrol is a lot more harmfull these day. The cure was worse than thu diease. I was a mechanic for 6 years and spent hours up to my armpits in the stuff. These days I walk off the forecourt when my car is filling.

Just to add to the techno stuff, the rating is a comparison. 96 octane means that the petrol has the same anti knock properties as a mixture of 96% ISO octane and 4% normal heptane. GO mad if you choose and read all about it.

http://www.sizes.com/units/octane_number.htm

Over and out

[Mongoose]

Not sure about 98 but all the other fuels in Auckers come out of the the one tap down in Wiri. The only differences are the additives and the sign on the truck.

Kind of like a post mix soft drink.
They are all base water and then an additve or two are added and you have coke.[/QUOTE]

Some are no different at all, they even pump out of the same port tanks, so it is only ther colour of the truck that is the difference.

[Drunken Monkey]

Here's an interesting thought.

Coming back from Auckland last time on the bike, I inadvertantly put a tank of 91 in it. Amazingly, I went 43km further than usual before the fuel light came on and I could not tell the difference in performance.

Still hoists the front at 120 in 2nd and all.

Queer huh :spudwhat:

Dude, your bike is EFI = the system will advance/retard the timing to accomodate the change in 'knock' the different fuels have. With the timing and fuel feed adjusted to suit the different type of fuel, your plugs wouldn't have been subjected to combustion conditions they weren't designed for. Carb'd engines don't have this luxury.
There would have been a minor performance difference, but probably only something you could've shown with accurate meters (rather than the good old fashioned (gut-o-meter). I add this only counts if you're up in the high revs where the engine may be prone to knock (and thus be forced to retard the timing more than normal). If you're not using the very top of your rev range, you shouldn't be as at risk to knock and therefore shouldn't notice a performance change.
Not sure about the difference in economy. I can't remember what other changes occur. I have 1 basic rule, if it's old (<1985) or a force fed or otherwise high performance engine (ie more likely to suffer from 'knock') always use the highest octane fuel you can get. If it's a late model (>1990) runabout then 91 should be fine.

I do assume you meant your 2K3 GSX-R600 here...

[Ghost Lemur]

Does that mean I should run my '81 cb250rs on 96?

[marty]

avgas has lead additives still as it is not used on the road, and does not come under the rules for emmision control. there are issues associated with knock in aviation engines - not the least that it cannot be heard by the pilot, and unless they are electronic ignition (high-end $250k machines) they have no method of inflight advance or retard. they are designed for best performance over a range of operation.

[marty]

from memory an aviation engine is set to about 25 degrees BTDC. i only work on gas turbine engines (with 100000 hp...mmmmmmm) but one of the guys i work with is a piston engine overhaul specialist. i'll ask him in the morning. i do know that AVGAS is less volatile the MOGAS, so it does not tend to cause vapour locks in lines when heated - not a huge problem in your car on the motorway, but at 5000 feet........

[geoffm]

Dude, your bike is EFI = the system will advance/retard the timing to accomodate the change in 'knock' the different fuels have. With the timing and fuel feed adjusted to suit the different type of fuel, your plugs wouldn't have been subjected to combustion conditions they weren't designed for. Carb'd engines don't have this luxury.

Only true if it has a knock sensor. Map EFI systems are basically electronic carbs - engine RPM = this much, then squirt for this long. most have throttle position sensors as well

[maybe]

Mate and I filled up in the Wairarapa couple of weekends ago and had nothing but problems since with both of bikes backfiring and not running to well.....mate just spent a couple hundred getting the carbs done to try and fix the prob - which it did - as for me, mine are booked into TSS Lower Hutt (plug there)

[FROSTY:Me]

I tell ya what Ive seen how casual they are filling them tanks --I would always suggest a simple carb drain if ya suddenly get bad performance after filling up

[Mongoose]

avgas has lead additives still as it is not used on the road, and does not come under the rules for emmision control. there are issues associated with knock in aviation engines - not the least that it cannot be heard by the pilot, and unless they are electronic ignition (high-end $250k machines) they have no method of inflight advance or retard. they are designed for best performance over a range of operation.

Is AVGAS not also *dryer* than MOGAS? Just wondered as i have heard this, oily fuel is not too hot at high altitude or some such thing?

[Big Dog]

Hey BD,
I thought Gull was trucked up from the Mount ??


F/F

Dunno TBH but there was a Gull truck exiting wiri when I was down there about 18 months ago.

[Big Dog]

Some are no different at all, they even pump out of the same port tanks, so it is only ther colour of the truck that is the difference.

Not quite, Vortex has detergents, surfactants etc. added. In different parts of the country anti-thickening agents are added to prevent starving in particularly cold conditions (at different times of the year).

Most fuels have the same or similar additives, the only difference being the amount of "seasoning" for each additive.

Most fuels also have different dyes used as they react to the additives.

Vortex is yellower than Synergy. Bp is slight green tinge, shell is a darker red etc. (I'm not mad get a small sample of each and hold them up to the light). Sometimes trucks will deliver to a site from a different company that has run out on short notice as a favour, and expect the same in return later.

I find my bike runs better on vortex. Ran rough at first, but once all the the black shit stoped comming out the other end all good.

Yes I work for Caltex. Yes I have a fuel card.
But I was a loyal customer for 12 years before I worked for them, and as long as I am paying for my own fuel card it will be Caltex.

I have to fill up at bp on the coro loop to make it back. My bike runs rough at idle for at least two tanks later.

I don't think Bp have shitty fuel just that small engines prefer to use the same fuel consistently.

[Posh Tourer :P]

Does that mean I should run my '81 cb250rs on 96?

Probably.....

[Drunken Monkey]

Only true if it has a knock sensor. Map EFI systems are basically electronic carbs - engine RPM = this much, then squirt for this long. most have throttle position sensors as well

Ah yes, further research leads me to beleive the Gixxer's open loop feedback comes from the O2 sensor, and no knock sensor is present. Still, the O2 sensor should give the computer enough information to adjust the fuel injection as required, based on too much/not enough O2 than expected at any given situation. Not sure if a different octance fuel could effect this though?
Don't all EFI systems have to have a TPS? How else would the system know how much throttle you are giving it otherwise?

[Firefight]

Dunno TBH but there was a Gull truck exiting wiri when I was down there about 18 months ago.

Hey again BD, Checked it out on the website, it comes from the Mount, the more I think about it , Ia'm sure we have discussed this B4, some people were claiming that Gull was cleaner than the shit that comes from Marsden Pt, not sure why you saw a gull tanker at WORSL(wiri oil terminal), can,t say as I have seen any there, I go there from time to time, anyway some one may be able to find the posts about the difference in fuel quality.

Web is www.gull.co.nz.

Firefight.