Water temp/oil pressure

[Rambo]

That's an interesting article by the Opie expert. He knows his stuff and explains it well in laymen's terms

Incidentally, I used to check all oils (engine, gearbox, transmission etc...) used by the Coal Board in the Scottish area. You needed to take a lot of care when the viscosity test at 100C was carried out for obvious reasons. But not as much as for the flash point. It led to many an interesting flash/flare in the fume cupboard on a dark winters day

[Rice crispy]

I went 10 30 synthetic this year instead of 10 40 and I notice how much smoother mine runs, oil pressure is slightly lower but still 2.5 bar when hot

[lotusflasherman]

I went 10 30 synthetic this year instead of 10 40 and I notice how much smoother mine runs, oil pressure is slightly lower but still 2.5 bar when hot

I can only conclude that your old oil had lumps in it...

[Simon_P]

Definitely not missing the point - I understand well that the reference temperature for defining SAE viscosity is 100 oC and the W grading which I recall are taken at different temperatures for each grade . There is much more to consider than viscosity, and with the bypass valve open, which will happen earlier for a more viscose oil there will be less oil flowing to where it is needed.

Each to their own, but for my part I don't see any advantages in using 60 grade oil particularly in an engine with tight clearances designed for 30 grade oil.