Perplexity gives me a few good tidbits of information too.
Based on the search results provided, I can offer some information about the fuel options available in Australia in the late 1960s:
1. In 1967, there were two main grades of fuel available:
- Standard fuel, with an octane rating of 92 RON (Research Octane Number)[3].
- Super fuel, with an octane rating of 97 RON[2][3].
2. The octane ratings changed slightly over time:
- In April 1964, Super fuel was upgraded to 97 RON[3].
- In August 1968, Super fuel was further upgraded to 98 RON[3].
3. These fuel grades were leaded petrol, as unleaded petrol was not introduced until much later:
- Unleaded petrol (ULP) was introduced in Australia in January 1986, with a 91 RON rating for Regular ULP[3].
- Premium Unleaded Petrol (PULP) was also introduced in 1986 with a 96 RON rating[3].
4. The compression ratios of engines at the time were designed to work with these fuel grades. For example:
- The 1967 Ford XR GT had a compression ratio of 9.7:1, which was suitable for the Super fuel of that era[2].
It's worth noting that the fuel quality and octane ratings have evolved significantly since the 1960s, with the introduction of unleaded fuels, higher octane ratings, and stricter environmental standards.
Citations:
[1]
https://www.energy.gov.au/sites/default ... _2018.xlsx[2]
https://www.fordforums.com.au/showthread.php?t=11486825[3]
http://www.fefcholden.org.au/techinfo/tech003.html[4]
https://www.bitre.gov.au/sites/default/files/is_082.pdf[5]
https://www.aph.gov.au/About_Parliament ... sStandards
