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.