Same as their Type A with Triphenyl Phosphate additive. Similar to AeroShell's straight weight "Plus" formula. Offers a more antiwear plus anti-corrosion.
No not this one but did in the previous PA-11's C-90. It was ok but eventually I went back to W80 Shell as my winter flying declined and I preheated anyway.
I'm not flying much lately so straight weight 40 is installed. It tends to stick around longer on parts than a 20W-50 that's a 20W at room temps. My experience with 20W-50's is they can loose oil pressure (minor but nonetheless) after 25 hrs of use. Maybe the VI improvers eventually get cut up.