History of Aus Petrol octane

[mick taylor]

Anyone know the facts of Australia's history of petrol octane ratings.

Just off the cuff.
By the looks of Holden from 1949 compression being 6.5:1 and they ran on Standard fuel and no Holden ran on Super fuel until the red motor in late 1963 with 8.8:1 high compression and the low compression 149 was 7.8:1 running Standard fuel.
So this points to the ratings came up as the years went by, not to mention the last of the grey motors had gone up to 7.2:1 by 1960.

Then we see in 1971 the HQ Holden has a low compression 173 with a whopping 8.3:1 on Standard fuel.

Valiant Slant 6 had 8.2:1 did they all run on standard, the last VF Pacer I seen claimed at 9.2:1 this maybe true ? but the VE slant 6 with 2v caby were still 8.3:1

XK to XP 144 low comp was 7.5:1 and high comp were up to 8.7:1 and the XR Falcon 200 had 9.2:1 but the 1967 XR GT was 9.7:1 I think. then the 1971 XY GT is 11:1 and the 1970 HT 350GTS 10.25:1

I only remember Standard rated at 89 and Super at 97 Octane I believe.
Then we got that crap unleaded at 91 or sometimes rated at 92 but I do not remember when the 95 Octane came in, or 95 was not Australia wide at first.

I remember a low lead fuel or half lead came out as well in about 1989 if I remember right and I do not remember the Octane of it, it may not of been displayed, it may of been 95 or so maybe I tried it once in my HX 308 and it was fine.

Everyone I have asked has not a clue of such things. how can we just let such as our History be washed away.

[Franco Cozzo]

Surely leaded fuel had a higher octane rating than unleaded? Or if not maybe the lead additive made the fuel really resistant to detonation?

Whats the go with all the high compression V8 engines of the 1960s from the USA prior to emissions regulations?

Even things like the Kingswood 308 making more power than the EFI 304 in the VN, which had 8.4:1 compression ratio and some other mods because of ****ty unleaded fuel at the time?

While we're talking unleaded fuel it would be interesting to talk about sulfur content of our fuels too compared to say Europe/USA and Japan, a lot of the reason we don't get the good engines from Japan is we still sell 91 octane (Mazda gives us low compression crippled Skyactiv engines) Honda also had dramas in the 1990s/00s with our fuel and same with BMW, we completely missed out on a series of their 3L I6 due to fuel sulfur content, so we get the low compression/performance variations to this day.

It'll be good to get citation from our members who were around at the time of the leaded/unleaded change over.

[Itsme]

Originally Posted by Franco Cozzo

Surely leaded fuel had a higher octane rating than unleaded? Or if not maybe the lead additive made the fuel really resistant to detonation?

Whats the go with all the high compression V8 engines of the 1960s from the USA prior to emissions regulations?

Even things like the Kingswood 308 making more power than the EFI 304 in the VN, which had 8.4:1 compression ratio and some other mods because of ****ty unleaded fuel at the time?

While we're talking unleaded fuel it would be interesting to talk about sulfur content of our fuels too compared to say Europe/USA and Japan, a lot of the reason we don't get the good engines from Japan is we still sell 91 octane (Mazda gives us low compression crippled Skyactiv engines) Honda also had dramas in the 1990s/00s with our fuel and same with BMW, we completely missed out on a series of their 3L I6 due to fuel sulfur content, so we get the low compression/performance variations to this day.

It'll be good to get citation from our members who were around at the time of the leaded/unleaded change over.

Lead in the fuel certainly did raise the octane rating and by the way it took a long time before leaded fuel was phased out in Australia.
Unleaded introduced in mid 80's and I think lead fuel finally phased out in the 90's

[whynot]

https://fordforums.com.au/showthread.php?t=11332626

https://www.uniquecarsandparts.com.au/petrol_oil

[Itsme]

Originally Posted by mick taylor

Anyone know the facts of Australia's history of petrol octane ratings.

Just off the cuff.
By the looks of Holden from 1949 compression being 6.5:1 and they ran on Standard fuel and no Holden ran on Super fuel until the red motor in late 1963 with 8.8:1 high compression and the low compression 149 was 7.8:1 running Standard fuel.
So this points to the ratings came up as the years went by, not to mention the last of the grey motors had gone up to 7.2:1 by 1960.

Then we see in 1971 the HQ Holden has a low compression 173 with a whopping 8.3:1 on Standard fuel.

Valiant Slant 6 had 8.2:1 did they all run on standard, the last VF Pacer I seen claimed at 9.2:1 this maybe true ? but the VE slant 6 with 2v caby were still 8.3:1

XK to XP 144 low comp was 7.5:1 and high comp were up to 8.7:1 and the XR Falcon 200 had 9.2:1 but the 1967 XR GT was 9.7:1 I think. then the 1971 XY GT is 11:1 and the 1970 HT 350GTS 10.25:1

I only remember Standard rated at 89 and Super at 97 Octane I believe.
Then we got that crap unleaded at 91 or sometimes rated at 92 but I do not remember when the 95 Octane came in, or 95 was not Australia wide at first.

I remember a low lead fuel or half lead came out as well in about 1989 if I remember right and I do not remember the Octane of it, it may not of been displayed, it may of been 95 or so maybe I tried it once in my HX 308 and it was fine.

Everyone I have asked has not a clue of such things. how can we just let such as our History be washed away.

Most likely confusing yourself as some leaded fuel pumps allowed you to mix standard with super depending on what type of engine compression you ran in the old cars.

[Franco Cozzo]

Originally Posted by Officemanager

Lead in the fuel certainly did raise the octane rating and by the way it took a long time before leaded fuel was phased out in Australia.
Unleaded introduced in mid 80's and I think lead fuel finally phased out in the 90's

Technically it was only completely phased out for automotive use in 2019 - you could buy leaded racing fuels up until last year:

https://motorsport.org.au/media/news...ments-for-2019

https://www.legislation.gov.au/Detai...0Material/Text

This legislation it appears there was a discussion on banning 91 octane fuel which was supported by the automotive industry but knocked back on cost grounds due to increasing cost at the pump.

We're not going to get low sulfur fuels until 2027, so I guess we've got the best part of another decade before we start getting more modern internal combustion engine designs through.

I guess its going to keep the dreaded petrol particulate filter away from us for a while yet.

There's a lot of whinging online about Australia's ban on leaded racing fuels, if it was just octane that was the issue then why couldn't they make changes to fuel system and use E85? There has to be more to it than just octane rating.

Pump E85 from United has an octane rating of 107, racing E85 is higher even still.

[Rallye Sport]

Leaded fuel for general sale was phased out at the start of the year 2000. I remember certain BP's having 100 octane avgas pumps out the back.
Barbagallo/ Wanneroo park had a pump in operation for a while after the ban that we'd buy it from. I must check next time I'm up there its probably in the scrap metal heap, would make a good garage ornament.

[Dr Terry]

Originally Posted by Franco Cozzo

Whats the go with all the high compression V8 engines of the 1960s from the USA prior to emissions regulations?

Even things like the Kingswood 308 making more power than the EFI 304 in the VN, which had 8.4:1 compression ratio and some other mods because of ****ty unleaded fuel at the time?

During the 60s it we often added Avgas to super for high comp engines, but factory motors with anything more than 10:1 weren't commonplace. GT-HOs & XU1s were the ones we saw. US imports were less common. During the early 70s we had a company called Fleetwing ??. They sold 100 octane at the pump, that made life easy.

No Kingswood 308 had anywhere here the power of a stock VN 304. The best leaded 308 carby motor (not counting L34) was the HJ which was listed at 250 bhp & the VN 304 EFI was 165 kW.

250 bhp equates to 186 kW but this is Gross power, not Net. While there is no direct conversion factor 186 kw Gross would be around 120-130 kw Net. You can't compare power numbers from the 60s & early 70s to today's.

The Holden EFI V8 was a very good engine for its day, especially compared to the EB Ford 5.0. Modern engines rely less on compression & octane, with most improvements seen in camshaft profile, head flow & electronic management of fuel & ignition.

Dr Terry

[Dr Terry]

Originally Posted by Officemanager

Most likely confusing yourself as some leaded fuel pumps allowed you to mix standard with super depending on what type of engine compression you ran in the old cars.

Yes, I remember these well. They were introduced in 1964/65 as the BP MultiMix or SuperMix.

The price gap between Standard & Super was starting to increase, with many old 50s cars still on the road quite happy to run on standard, or something slightly better.

With the increase of the use in Super petrol many other brand servos were removing their standard pumps altogether.

It was a great marketing idea.

Dr Terry

[Blue Dog]

In the 1970's there was a servo located on Anzac Parade Kingsford NSW that sold higher octane petrol than what was available at the regular servo's.
It was a stones throw from K-Mac Suspension.

[simon varley]

Originally Posted by Franco Cozzo

We're not going to get low sulfur fuels until 2027, so I guess we've got the best part of another decade before we start getting more modern internal combustion engine designs through.

the hilarious thing is, that by then most other advanced countries will be well on their way to banning internal combustion engines entirely, so there won't be any decent ones to choose from!

[rare ss]

Shell RF100 was great for me old VK 308.. used to love it.. sigh

[mick taylor]

Originally Posted by Officemanager

Most likely confusing yourself as some leaded fuel pumps allowed you to mix standard with super depending on what type of engine compression you ran in the old cars.

No I pumped fuel back in 1976 and had some people want me to mix half Standard and half Super.

But It was around about 1990 or so that for about a year one brand of service station was advertising a half lead, I filled up with this once, it was a station half way between the gold coast and Brisbane on the old highway on the going up to bris side. I have a photo of that station in a book I have showing off a hotted up commodore, I would have to find it.

[mick taylor]

Originally Posted by Franco Cozzo

Surely leaded fuel had a higher octane rating than unleaded? Or if not maybe the lead additive made the fuel really resistant to detonation?

Whats the go with all the high compression V8 engines of the 1960s from the USA prior to emissions regulations?

Even things like the Kingswood 308 making more power than the EFI 304 in the VN, which had 8.4:1 compression ratio and some other mods because of ****ty unleaded fuel at the time?

While we're talking unleaded fuel it would be interesting to talk about sulfur content of our fuels too compared to say Europe/USA and Japan, a lot of the reason we don't get the good engines from Japan is we still sell 91 octane (Mazda gives us low compression crippled Skyactiv engines) Honda also had dramas in the 1990s/00s with our fuel and same with BMW, we completely missed out on a series of their 3L I6 due to fuel sulfur content, so we get the low compression/performance variations to this day.

It'll be good to get citation from our members who were around at the time of the leaded/unleaded change over.

USA went and pushed unleaded in 1972 you could use leaded in them cars and they also had a half lead fuel as well, so you could run any fuel until 1975 when the cat converters came out, then it was only unleaded one could use in cars built from 1975.
Using higher octane in a low compression engine like 8.5:1 is no point.
The USA unleaded fuel was about our 92 octane rating in RON, but the USA use PON rating system.

PON 85 to 87 is our RON 91 to 92
PON 89 to 90 is our RON 94 to 95
PON 90 to 94 is our RON 95 to 98

The reason why such a low rating for the USA in 1972 and such was I believe due to that it takes less to make and crack down, so sadly they must of had to come up with one more new extra fuel over the whole USA so the EPA opted for the low octane crap. so new cars had to drop compression to crap like 8.5:1 and that's why they were so gutless.

So in 1971 USA would of had in the main 3 fuels, so one had 3 different pumps at a station and in 1972 you had 4 of them, but what if you had 6 different pumps ? so they had to wait some years before unleaded came out with higher octanes.

Japan was the first country to go to unleaded fuel, look at a Kawasaki Z9 the weapon road bike in the days, 1973 it only had 8.5:1 compression.

Unleaded fuel is much better than leaded fuel for engines as the lead fuel builds up crap on the plugs and all, not that unleaded fuel is better for humans because it's not in fact, it's worse by far, don't wash your hands in it the toxic can get into your blood stream and it's bad for underground water contamination even after it's burnt and that's why the USA was forced to go all E10 as they took that toxic chemical out and replaced it with E10. now with E10 you can wash your hands in it, just like with leaded fuel you could. not that you should but with out that fear.

[mick taylor]

Originally Posted by Dr Terry

During the 60s it we often added Avgas to super for high comp engines, but factory motors with anything more than 10:1 weren't commonplace. GT-HOs & XU1s were the ones we saw. US imports were less common. During the early 70s we had a company called Fleetwing ??. They sold 100 octane at the pump, that made life easy.

No Kingswood 308 had anywhere here the power of a stock VN 304. The best leaded 308 carby motor (not counting L34) was the HJ which was listed at 250 bhp & the VN 304 EFI was 165 kW.

250 bhp equates to 186 kW but this is Gross power, not Net. While there is no direct conversion factor 186 kw Gross would be around 120-130 kw Net. You can't compare power numbers from the 60s & early 70s to today's.

The Holden EFI V8 was a very good engine for its day, especially compared to the EB Ford 5.0. Modern engines rely less on compression & octane, with most improvements seen in camshaft profile, head flow & electronic management of fuel & ignition.

Dr Terry

Look at the advancement's from the first Holden in 1949 and the compression jumping up from 6.5:1 to 6.8:1 and then to 7.0:1 and then topping off with a whopping 7.25:1 on Standard fuel of the days, now apart from advancement in the grey engine camshaft and all, I am sure that the Standard fuel Octane rating went up during them years, not to mention more again we can see with the Holden red motor, look at the jump to 7.7:1 in a 1963 low compression 149ci and then a whooping 8.3:1 in the 1971 173ci low compression. with 89 octane Standard in 1971 I remember a 87 octane as before that and what ever it was before that ?

Look at the new engines now VF V6 with 10.2:1 running on 95 octane, sure they can run on crap like 91 octane but the computed is retarding the spark timing to do so and all.

They have alloy heads and all mind, but look at the VS V6 with a iron head running 9.35:1 on crap like 91 octane, sure I heard my wife's VS V6 ping like a bastard directly when I would overtake on the highway but then it was fine until I hit 5000rpm then pinged to 5500 on Caltex 91 right from new, but it was a real good performing VS V6 fastest I have ever driven and I drove some that were ok and some were gutless crap right from new.