Correct Unleaded and or Premium

Westair · Correct Unleaded and or Premium

This is great link.

http://www.cvwc.com.au/info.html

Adam

i was going to ask this question but now i don't have to!
thanks

Brookie

This is a great link from Torque Cars in UK on Octane and/or RON ratings and why fuels differ

http://www.torquecars.com/articles/fuel-octane-ratings.php

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LittleOzzyBloke

hm same here...i've been swapping a bit...half unleaded ...half premium....was always worried about it...but now i use 98% premium and notice a huge difference in the power... Wink

Brookie

Premium seems way to go- extra power and slightly cooler running especially in hot conditions.

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aussiebug

Hmmm - there is in my opinion some misinformation on the sites suggested above.

The Canberra VW site says you'll get more power and better fuel economy using premium unleaded as it is a better fuel.

Welllll - maybe.

First - you might find this article on my site useful reading.
http://www.vw-resource.com/octane.html

The adverts about Premium giving you better fuel consumption is slightly misleading.

These fuels are slightly more dense than other fuels - they have more weight per litre and so has more fuel molecules per litre than other fuels. So if your Kombi comes equipped with a modern engine computer which senses the unused fuel in the exhaust and resets the mixture to suit, then yes - your Kombi will get better fuel economy with these new fuels.

But if your Kombi has the normal carburettor or mechanical FI and no engine computer (I think that covers 99.9% of Kombis) then you won't see any increase in fuel economy or performance when using the new style "ultimate" premium fuels.

And there is NO advantage in using a fuel with a higher octane than that recommended by the manufacturer - as my article above states, the octane rating is NOT a measure of how powerful the fuel is - it's just a measure of how well the fuel resists detonating/pinging.

All the stock compression aircooled VW engines from the 1500 up to the 2000 Kombi engine recommend 91 RON octane. That's exactly what normal unleaded in Australia is, so that's all you need unless there has been some modification or alteration to the engine requiring a higher octane rating.

regards

Brookie

Hi Welcome to the Forum.
Had read your webpage article before and your post is informative as well.

Only problem is that there is no guarantee Australian refineries are producing the claimed octane ratings.

For example in Western Australia we have only one refinery and that is BP.
The formula that BP uses for both unleaded and premiun is the only one by law that we can use in WA.
This was created by "brilliant" Embarassed

lobbying to our State Govt who were convinced that this formula is the cleanest in the world. Very Happy

There is only one other refinery in the world, another BP in BC Canada , that has same product.
This is was possibly done to stop the independants importing from Singapore and selling for up to 6 cents a litre less.
It is illegal to import fuel into WA even from the other States.

Piratekombi

There is also the possibility that the premium fuel has been diluted...
http://www.smh.com.au/articles/2007/12/18/1197740313527.html

I only use premium fuel with valve additive (rather than standard fuel) as our engine feels, to me, that it is running better... we seem to get better economy, and the engine just feels smoother. It is probably just my imagination, but I reckon Woger enjoys a tastier meal...

Gabbo's Run

I have tried the premium juice and to me it never seemed to make any difference. I just use the unleaded and when i think of it chuck in same additive. It runs fine to me which ever way i go.
I think what ever you are comfortable with, just go that way.

brian

aussiebug

Brookie

Gabbo's Run

thanks rob, i read you.

brian

Gabbo's Run

And thank yuou also mate.

you know who you are.

brian

the aussie trimmer

I have always used premium in all my VW’s; I also run a fuelstar tin canister and my cars do run better on premium, so I for one will keep on useing it.

Kinga

I was told by a very reputable VW mechanic that because VW engines are air cooled, they are designed to run at much hotter temps anyway.

So there wasn't the need to do anything extra to the valve set-up if rebuilding or to use an additive.

As for premium v regular unleaded, when you actually get what you pay for I notice the difference in my late model euro car (twin turbo 6 that specifies high octane fuel use).

The problem is that most of the time the high octane fuel performs no different to the regular now days (but the price difference is getting larger). I am really discerning about where I buy premium from to make sure its worth the premium price.

As for running high octane in VW's

I used to run my dual cab on Avgas (100 octane) every now and then just for fun. It certainly ran a lot better Very Happy

Keith D

In my Kombi there's no noticeable difference in performance or economy whether I use ULP or ULTRA.

My original handbook advises that 91 Octane petrol is the fuel requirement, which is the Octane rating of ULP.

Keith D

Brookie

W.A. Fuel is different then the rest of Australia-almost different than the rest of the world.
Quite a few years ago when fuel prices started to rise some independants were bringing petrol in from Singapore which was selling well below local prices.
As we have only one refinery some marketing genius convinced the Govt of the day that the petrol processed at BP Kwinana was the cleanest in the world.
Subsequently legislation was passed that ONLY this formula can be sold in W.A.
This means , like nearly happened a couple of years ago when stocks got low and Kwinana had a problem, we cannot import fuel from anywhere including Eastern States..... but we can import from Canada. This is from a BP Refinery out of Vancouver which just happens to be the only refinery in the world using the same formula. Twisted Evil

People who drive some of the late model turbos and drive over from east are shocked at difference in running and many have fuel readouts and cannot believe what we have here.
Hooray for aircooled VWs- most will run somehow on power kerosene through to Avgas and Scotch whiskey also.

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aussiebug

Weelll, probably NOT on Scotch wiskey - that's 60% water, so only 40% is alcohol, and ALL ethyl alcohol contains 40% used oxygen, so that means 40% of the 40% alcohol content of whiskey is not available to the engine. Better to use that to fuel yourself, so long as you aren't driving afterwards!

Even 10% ethanol (E10 petrol) makes a bug (or any carburetted engine) run 4% lean, and performance WILL suffer unless you increase the main jet size to richen the mixture back into stoichiometry (air/fuel balance).

The bug engine has hardened steel valve seats so it does not suffer from valve seat recession (leaded fuels stopped VSR in engines with "soft" cast iron heads).

The bug engine has exposed valve stems (no rubber caps), and phosphor bronze valve guides; so the valves get enough lubrication from the engine oil - they don't need the extra lubrication provided by the oily Tetra Ethyl Lead additive in leaded fuels (this lubrication was useful in cast iron heads to help lubricate valves stems).

The bug engine needs only 91RON (87AKI in the USA) octane for normal compression engines, and it doesn't matter HOW the refinery gets the 91 number. That number is only an anti-knock indicator, so buying a higher octane fuel does NOT help the engine at all.

BUT - some high octane fuels are also formulated as more dense fuels - there's more carbon and hydrogen atoms per litre, so there is a little more fuel in the fuel, if you follow that. That will make carburetted engines like the VW run a little richer, and of course we all know that richer means a little more power, so some higher octane fuels MIGHT help engines which are otherwise running a little on the lean side - but not because of the octane rating.

liam:-)