It seems that today the new diesels have extended their oil/filter service considerably. On the TD5 Discovery the service is 12,000 miles (but it does also have a centrifugal filter) & on the Fiat Ducato 2.0JTD it would appear that the service interval is between 12,000 miles & 20,000 miles. When compared with diesels of 7 years ago it was not uncommon to have an oil change at 4.5k & oil & filter at 7.5k. I cannot believe that this is down to improved design of the engine alone. The real change over the years is the use of synthetic oil, maybe there is also improvement in the filters. My question is, does this mean that the older diesels can be extended too - lets face it, fully synthetic oil was not used then. Thoughts?
Steve