Fuel quality. Any difference between companies?

**Cloggy** · 13th March 2009, 17:39

Originally Posted by trademe900

What about that 'Pack and Save' fuel though? Got a feeling that's fucking dodgy for some reason. 6 cent discounts from shopping there too. Could it be shit quality ?

Pak and Save get their fuel from BP, same with G.A.S., also BP.

**Ocean1** · 13th March 2009, 18:02

Originally Posted by Gubb

Like I said, it all comes in on the same boat. It's the same fuel.

Exactly correct.

Occasionally a shipment of imported fuel is slightly different, and may be delivered to just some ports, eventually being delivered to just some outlets. Even then it's usually noticable more by a slightly different smell than any relevant, quantifiable specification.

**dwnundabkr** · 13th March 2009, 18:42

for Bp,shell,caltex and mobil yes all from the same imports, gull is the only company which was importing its own fuel
the 98 from BP and the gull 96 was coming from singapore refinary now this info is about 4 years old so could not be that up to date.
when working for gull there where shipments that where getting as high as 100 plus octane rating

**Ocean1** · 13th March 2009, 20:20

Originally Posted by dwnundabkr

there where shipments that where getting as high as 100 plus octane rating

Research octane number. It's not exactly meaningless, but it’s a reference measurement, an indication of knock rate, (which is what actually matters), and which can't be calculated easily the way octane numbers are nowadays.

To define knock rate you buy a fuckoff big single cylinder engine specifically designed for the purpose and manufactured to a huge list of standards. You’ll need a sizeable wad of cash for that. Then you gas it up with a sample and mess with the adjustable compression, timing, mixture etc etc etc, until you get a set of numbers that describe exactly what the fuel's relevant combustion characteristics are.

Bear in mind the purpose of all this is to make sure the product meets a particular standard, not to prove it’s potency or value. A higher knock rate affects engine performance only if, firstly the engine management system is capable of recognising the minuscule difference in burn-rate, and secondly if the engine itself is designed to run it.

Motorcycles might trend towards what most might call the higher performance end of the automotive engine range, but their engine management systems are comparably crude. In short, gassing up with fuel beyond the octane rating your engine is designed to run is pointless.

**McWild** · 13th March 2009, 20:34

I'm a believer that every bike is different, just gotta play around and see what you like best. I've been using 95 from Mobil since I've had my bike, but I'm going to start playing with 91 as soon as I need to fill up again, once I get the bike back from the shop.

What do you guys think about two strokes?

**Hiflyer** · 15th March 2009, 13:48

hmmm shell nearly got wasted by the govt for their slogan "takes you further" so there was a big study done which proves it does in fact take you further, but only by 5% .. .. . must be the additives they put in.

**Monty69** · 17th March 2009, 16:28

The 1 time i filled up at challenge, my super reliable cbr was crippled with shit in the carbys causing it to run like a dying dog. Cost me $500 to get carbys and filter sorted. Followed mechanics advice i went back to good old shell. Im not sure what company is best but i knw which is worst.

**awayatc** · 18th March 2009, 04:36

$500 for carby and filter clean.......?
You gotta be kidding me!

**Monty69** · 18th March 2009, 15:58

Originally Posted by awayatc

$500 for carby and filter clean.......?
You gotta be kidding me!

They didnt know it was the carbys strait away, a lot of time was spent checking everything else to eliminate all possible problems. time is $. and $100 for new airfilter

**Dragon** · 18th March 2009, 16:45

Originally Posted by Nasty

Definately tell the difference in octane 91v98 .... I got 91 this time .. they were out of 98 ... I am spewing cos I couldn't get to another station .... the gas is crap!

I had the same thing happen to me and my car hates 91

**meowmix** · 18th March 2009, 17:15

I bought (and sold) an MR2, which still had a tank of 91. Two tankfulls of 95 later and there was a difference. The engine seemed to run alot smoother, probrally due to the timing being closer to where its meant to be.

On my carb'd bike however... I still use 95, mainly because as its air/oil cooled the temps aren't reliable, and I'd rather avoid any knocking.
Its a common misconception that 95 octane will give more power or better economy then 91, unless you have an ECU that detects the amount of timing advance it can give.

I worked at a petrol station once, (recently) and had to check the levels in the underground tanks. Those tanks are filthy, there is alot of sediment and gunk in there. Never fill up if the truck has refuelled the station recently.

And as for the topic, I think more then what company you buy from, you should watch the cleanliness of the station. The old, dirty, poor back country station will go a looong time without cleaning their tanks.

**awayatc** · 18th March 2009, 17:29

but also a loooong time between that station's refuels.....

**sparky.scott** · 18th March 2009, 18:51

[QUOTE=meowmix;1986703]Its a common misconception that 95 octane will give more power or better economy then 91, unless you have an ECU that detects the amount of timing advance it can give.

[QUOTE]

Ok i work on cars and the likes everyday and i know this but recently ive changed to 95 from 91 on my bike and ive found that my fuel economy has improved by about 20kms per tank, the bikes revs seemed to have dropped by about 500rpm when sitting at 100kms and to top it off the bike seems to have more power too.

Not sure what to make of it seeing as my bike is carbd and fairly simple really.