Been using the Nulon Full Synthetic 10W-40 Hi-Tech Fast Flowing Engine Oil in my engine for years, change it every 5,000 kms. Maybe overkill??? Dunno, but like to think the engine will last. My last car was a 1985 XF optioned with 3.3 litre engine. It had done 330,000kms + when I sold it. Oil was changed every 5,000kms. It didn't burn any oil that I noticed. I think oil change frequency is as important as quality of oil.... as long as you use a similar oil viscosity as recommended by factory.
Cheers
