What they don't say is that different oil companies started operating the engines in different ways to begin with, and it took many years before standardization was possible at ASTM. And ASTM was much more North-America focused than ASTM International is today.
By that time there were two main methods of conducting the test in the USA, known as the "Research" method and the "Motor" method. These are different ways of operating the same test engine. These antiknock numbers could be quite a bit different from each other, and different oil companies and automotive companies had developed their preferences.
In Europe they had basically started out using the Research method alone and stuck with it for commerce. This value is normally consistently higher than the Motor method.
Full standardization in the USA was a bureaucratic compromise so it ended up (R+M)/2, so if anyone was to do any whining it would be equal whining for all.
Vendors didn't complain, you need two of the reference engines anyway so you can run both methods at the same time:
TIL, thanks. The downside of being non-American on an American-dominated platform is you'll continuously get trapped in Americans running their own standards no one else uses or even knows about... sigh
https://cfrengines.com/about/
What they don't say is that different oil companies started operating the engines in different ways to begin with, and it took many years before standardization was possible at ASTM. And ASTM was much more North-America focused than ASTM International is today.
By that time there were two main methods of conducting the test in the USA, known as the "Research" method and the "Motor" method. These are different ways of operating the same test engine. These antiknock numbers could be quite a bit different from each other, and different oil companies and automotive companies had developed their preferences.
In Europe they had basically started out using the Research method alone and stuck with it for commerce. This value is normally consistently higher than the Motor method.
Full standardization in the USA was a bureaucratic compromise so it ended up (R+M)/2, so if anyone was to do any whining it would be equal whining for all.
Vendors didn't complain, you need two of the reference engines anyway so you can run both methods at the same time:
https://event.corelab.com/uploads/F1F2%20Product%20Brochure%...