I had a old 400,000km subaru that used to display the oil light on hot days when at idle. Because this was a banger I only put cheap super market oil in it. One day I actually had to buy proper good quality oil and the light went out.
You have a 270,000km engine so it is an old engine so I would suggest you use "old" engine oil that some car companies make. It is just a tad thicker at operating temperatures, still lubricates well and provides the amount of back pressure the pump is expecting.
Garry
REMLR 243
2007 Range Rover Sport TDV6
1977 FC 101
1976 Jaguar XJ12C
1973 Haflinger AP700
1971 Jaguar V12 E-Type Series 3 Roadster
1957 Series 1 88"
1957 Series 1 88" Station Wagon
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