Don't dispute what you say but - recently went to see a 'for sale' TD4. The seller said it had just had an oil change at Kwik Fit. Looked at dipstick, the oil was filthy!
Incidentally my Millers full synth (Trident 5W40) costs £15 per 5 litres (car takes 6) and filter is £4.03.
I must admit I...