Mobil Super S 10w40 at the moment, with Proma MBL8 additive to shut those damn lifters up :lol:
Also use either Valvoline XLD Premium or Fuchs Super Titan either 10w40 or 15w40. All fully synthetic.
I find the viscosities is the factor over the synth vs semi synth debate. Running a slightly thicker fully synthetic oil on an older car is fine in my opinion.