Octane value in the sixties

[Michiel]

I know that in the sixties, when my car was made , a variety of fuels was available, like standard, extra premium et cetera. But to get an idea, what were the octane ratings/values of these fuels. Is there a contributor with an excellent memory amongst us?

[Myrtles Man]

Friday 17th March 1967

Star grading of petrol was introduced in the UK based on a British Standard set of octane ratings. Under this system one star was the lowest grade, 2 star was 92 octane, 3 star 95 octane 4 star 98 octane and 5 star 101 octane. The lower end was for the low tuned/low compression older design of engine, the middle range for more modern higher compression engines and five star was for large, fast and powerful engines. Most cars would run happily on three star petrol (assuming the timing was set correctly) but most motorists seemed to believe that four star was ‘better’. Most stations offered two, three, four and five star grades.

(Lifted from 365 Days of Motoring website - Google is your friend)

[Michiel]

So maybe my humble automobile was always driven with 95 octane fuel at the time... same as modern E10

[rocco]

I don't think 3-star fuel is the same as E10 is it?

The old star rating would have contained lead for a start. I'm not sure whether they also contained ethanol back then though.

[Michiel]

No, with regard to ignition settings. But that's another topic

[geoberni]

I don't think 3-star fuel is the same as E10 is it?

The old star rating would have contained lead for a start. I'm not sure whether they also contained ethanol back then though.

A lot of petrol contained ethanol. There's loads about it online. But nobody got uptight about it like now, possibly because the amount of alcohol additive wasn't published.
At one point, early 1920s, ethanol was used instead of lead as an anti-knock additive.

Take a look at this timeline and you can see where the different corporate giants of the day had an influence.
The 1920s and 30s are particularly interesting.

https://en.wikipedia.org/wiki/Timeline_of_alcohol_fuel

In the UK, one of the biggest sellers of ethanol blend post-WWII was Cleveland Discol; brought out by ESSO in 1958, the brand disappeared in the early 70s. TV Advert here from 1966:
https://youtu.be/4uEqqlqqf4Q

[rocco]

Very interesting stuff, thanks.

I've never learned as much on any other forum, I'm so glad this place exists and appreciate all the info. from everyone.