Oil, Oil Or Oil?

[Beastie 1]

Please stop talking rubbish.

 

 

Hmmm - I've just re read my last post and I'm going to have to put my hands up on that one 'cos it's a cock up. Still, it does have 2 redeeming points: Firstly it serves me right for trying to be a smart ass and secondly it serves as a good reminder that I should have re read some of the facts since it's 20 years since I last set foot in a fluids laboratory. My mistake.

 

I do not care how you measure viscosity, whether with a cup, brookfield, use centipoise, centistokes etc etc as an oil gets hotter its viscosity gets lower.

 

I'll freely admit to my error but I'm afraid that you too are not quite correct: It matters very much how you measure viscosity. I was correct earlier in stating that it's a measure of a fluids resistance to deform under shear stress. Engineers could in theory develop any number of ways to measure that property. My earlier error was in suggesting that viscosity measurement on the Stokes scale is factored with temperature whereas in fact what I erroneously described was co-efficient of viscosity on the Stokes scale. However viscosity on the SAE scale is a co-efficient measurement and that's the whole point of the SAE scale: The viscosity of a multigrade oil can get higher as the temperature rises. Yes the oil gets thinner but its SAE viscosity increases. It's purely because temperature is factored into the calculation and it was expressed this way to make oil grades easier to understand: If someone asks you what oil you use you don't have to check the ambient temperature you can just say "10/40" rather than sticking a thermometer in your sump and saying "40 centiStokes".

 

Maybe you should pull that "devils advocado (no not a spelling mistake) hat" from off your eyes and get aquainted with facts, reading those threads mentioned above should help.

 

yeah yeah - if it makes you feel better about it then - but you'd better have some formal eduction in fluid mechanics yourself if you're reckoning you can advise on what to read Seriously though - It was also my error to be so antagonistic towards you in the original post so it's poetic justice that I was careless enough to make a mess of my argument; an argument which is stopping here on my part because it's not helping the topic one iota. I hope that you don't take any more offence and I hope that anyone trying to learn anything about lubrication hasn't been bored out of their mind