Interesting observation around the use of multi grade in the Mini regarding the high shear in the gearbox. It is definitely true that it stuffs up the multi-grade oil due to the breakup of the friction modifiers, the stuff they add to make an oil multi-grade. It makes perfect sense. In one of the write-ups I found on the inter-web they actually refer to the A-series as fitted to the Mini as a case in point.
Now you can get Delo Silver SAE40 with a good dose of ZDDP. I just don't know what the effect on cold start will be.
Now you can get Delo Silver SAE40 with a good dose of ZDDP. I just don't know what the effect on cold start will be.