My car has 345,000 km. I'm going to change the oil tomorrow since since I just drove cross country (3700km) and I'm going to use high mileage oil and then in October I'll put in low weight synthetic in preparation for the extreme cold that comes every year....

 

For the price and performance for me; it's hard to beat Mobil 1 and Valvoline Full Synthetic 5w-30. It's the perfect year round oil and is sold everywhere for only a few dollars more than the cheap stuff. ($22-$26 for 5 quarts)

Been running both brands ever since synthetic oils hit the market and have never had any type of oil related failure and all of my engines with more then 200k miles on them still looked spotless on the inside with no gunk or sludge buildup at all.

 

5-30 synthetic Orileys

 

I use triple QX 5w-30 semi synthetic oil, and Crosland filters (air, oil, fuel, pollen) on my x type (sovereign) 2008 2.0d estate. which I service every 12mths or 12500 which ever comes first. I've had no problems in the 2 and a bit years since I've owned the JAGUAR