ONe of our top people in BC, who has in fact worked on loads of Jag engines told me..the best oil mout there for these engines in 20-50, preferably made by Penzoil, or Quaker State.
Straight weight oil is not reccomended.....If the car is used in cooler times a slightly thinner oil may be used. However 20- 50 is what we used as long as it did not get too cold.
