My father has a long history of collecting Mobilgas that started with his grandfsther and then himself working as a delivery driver in Southern California in the 50s. A friend of his gave him the attached photograph 30 years ago and has never been able to find any information on the torture test. I am hoping someone here can help with that.
Your best chance of finding something on this is to temporarily join "newspaper.com" or one of the other newspaper database websites. They usually give you 1 month free and then start charging $20 a month. The newspapers they have generally go back to the 1920s or so. Then do a search for "Mobil" and "Torture Test" together, and maybe something will pop up. Just remember to cancel your subscription before your trial is over,
The key to doing this is to have unique search terms. Searching just Mobil will give you a zillion different newspapers articles.
I've had very good luck using this source to find obscure information. It's likely they advertised this in newspapers somewhere.
Paul, I just did a regular 'net search, not a newspaper search. Unfortunately, I don't remember the exact search terms I used. I alternate between Google and Duck Duck Go as my search engines, and I think this was a Google search.