60’000 miles on cheap supermarket oil...

[Tony Griffiths]

Impressive results - the 2000-mile oil change interval might have assisted of course. Unfortunately, our Sevens cannot emulate the modern car with its potential for 20,000 to 25,000 oil-change intervals (or computer allocated distanced based on driving styles and journey types). Long gaps between changes are, of course, driven by fleets reducing servicing costs and helped by special oils and modern engines with minimal piston blow-by, highly efficient air and oil cleaners, tightly controlled running temperatures, a very quick warm-up from cold, precisely-metered fuel injection, a large sump and long, steady-speed motorway journeys.
There was talk at one time of engines never needing an oil change but one of my ex-pupils, who'd worked on this problem at Ricardo during the 1980s, said it was hopeless and they could never make it work satisfactorily. I asked her which engine maker had commissioned the work, but she grinned and said, "That's a secret, but we did get up to over 100,000 miles with an automatic top-up system. Unfortunately, the target was 250,000 for a vehicle running short journeys in cold conditions."
Today I hear that some truck engines (they do have large sumps) can manage 50,000 miles per oil change and with modern oils, one wonders if a car could, too? Probably not: https://www.youtube.com/watch?v=KC-SxrsgEwo and https://www.youtube.com/watch?v=Po00OqaMIQ8