Hi All

I have an old Audi A4 which consumes a lot of oil and has done for years. MOT test fine and no obvious leaks nor particularly smokey. We have been using 5w30 fully synthetic oil and to be honest given how long a litre of it lasts (around 400 miles for a litre) I can't imagine whatever we put in it would make much difference.

I have looked online and some seem to say to use this oil and some mineral oil. Also, I was wondering if a thicker one would be better (assume 5w40 is thicker?).

Will changing to a synthetic 5w40 or even to mineral oil make any difference?

Any oil / engine buffs out there?

Thanks

Lee.