Ive tried every oil possible and by far the best for performance gains is the expensive Shell Ultra 5w30 so far ive only been able to buy it in litre bottles , couple it with shell Vpower which Im led to beleive is now 100RON, I used the above in my M3, EVO6 and scooby STi when I had them I also used Bg44K fuel cleaner and this really really works, it will change your car its like a slight chiping of the ECU in terms of performance is the best way I can describe it especially if you have a high mileage car like I have
Though it still amazes me how many people just turn their cars engine off straight away when they have been driving...........Im gob smaked as the oil burns onto the turbo and eventually will stuff the turbo completely