The reason I linked to the Honda prototype is that I think its the only instance of a fairly intelligent clean sheet 200 HP mid-range aircraft engine development in this century. I don’t think anything fundamental would have changed in their approach between 2003 and today. Honda has a broad background in developing engines for very different applications, so they are capable of understanding that each application is different, and that modified car engines (including their own) aren’t the way to go.
I’m not sure it would have sold well if Honda had marketed it, the existing engines have the substantial advantage of long developed aftermarket supply including hundreds of companies and somebody would have to develop a matching new airframe for any reasonable hope for success. However Honda does have a long tradition of successfully infiltrating established markets and a reputation as trustworthy in the US.
W.r.t to the original question using automotive oil, good article from Vlisser
https://generalaviationnews.com/2017/05/22/for-oils-its-all-about-the-chemistry/
Good article.
This is relevant
Ash-type detergents clean up dirty engines and are very good at neutralizing acids due to their high base numbers. That is all well and good, but the negative part is that ash type detergents can build up metallic-containing deposits in the combustion chamber.
to the use of Mobil 1 to clean up the piston rings in an aero engine. You can get pre-ignition. However, one would not use 100% Mobil 1. Maybe 1 quart out of 10 i.e. diluted to 10%, and then only for the last few hours of a service interval. Own risk of course, etc… (worked great for me).
