My car is due a service very soon - it's on AVS plan and suddenly it's using quite a bit of oil - is this normal i.e. I'm guessing viscosity has got very low so it's using more and more.
Also how much of std. oil can you mix with Longlife oil? (I've already used 0.5 litres of Catrol GTD).
Also how much of std. oil can you mix with Longlife oil? (I've already used 0.5 litres of Catrol GTD).