Apologies if this has been asked before, but the search function at the moment keeps throwing up a 'database error' whenever I try and use it! The family have just acquired a 2000 A6 2.5 TDi (160k miles) that has been maintained all its life on the AVS servicing system with the long-life oil. Looking at the fsh that came with the car it is apparent that this has equated to an oil change every 20k miles or so. Now, not being used to this system (and being a bit distrustful of such long service intervals tbh) I was thinking of giving the engine a flush and using Synta Gold fully synthetic oil instead , with changes every 10k. Are there any reasons why this shouldn't be done? This is my first experience of the V6 diesel, so any advice welcomed! Thanks.