quote:No you just need two points and graph (which he provided) it on logpaper. That's what I did You could solve it math wise. But this is quicker
Originally posted by Michael SR: [QUOTE] ]you can't calculate that unless the oil's viscosity vs temp graph is perfectly linear (or a known function). -michael
quote:Thanks Al! The outside temp was around 25C at night when I did the test. My water temp gauge is the stock oem one and doesnt have graduations. The water temp fully warms up pretty fast and just stays constant (around the middle of the gauge) no matter how hard I drive or whatever the outside temp is. I see no point charting water temp vs anything. I tested my oil temp again today in the hot afternoon, outside temp around 31C. This is what came up: 6 mins = 60C 9 mins = 70C 13 mins = 80C 19 mins = 85C The absolute max oil temp would go was 90C, and that is if Im going slowly uphill or slowly thru a shopping center basement carpark searching for a parking lot. Now I know why extensive idling is considered servere service. Normal city driving with lots of stop & go, around 85C. Highway driving, around 82.5C. The oil temp gauge is an awesome gauge for all you oil fanatics out there! The oil pressure gauge isnt really so useful. Max oil pressure is around 70psi (cold), 60psi (hot). I only got it bcos when installing the 4-way-t-adapter for the oil temp sender, I had provision for the oil pressure sender, so I decided to get it over with at one go.
Originally posted by Al: I'd be interested in seeing water temp vs oil temperature and outside temperature.
quote:Patman-he just want's to know what the viscosity of this oil at 85C bc that's where his oil temp is. So if that's the accurate temp of his oil he is running the equivalent of a high 50 wt oil compared to the 14.5 cSt (40 wt.) at 100C . He might just be better off with a 30 wt oil.
Originally posted by Patman: I don't understand the need to know the viscosity of an oil at 85C though. If you have an oil that is thicker at 100C, and then another which is thinner at 100C, chances are pretty strong that the thicker oil will still be thicker than the other one at 85C. So if you're comparing oils, why worry about the spec at 85C at all? Or are you just wondering for curiosity sake? Since water boils at 100C, I wonder how much moisture actually gets burned off if your oil temp is only 85C? I know there will be hot spots in the engine where the oil is hotter and can burn it off, but how effective is it if the overall average temp of the oil is colder?
quote:Still don't believe it, but when you have a minute I'd at least consider evaluating it Why have a test for the winter number too? You have 40 and 100C...CALCULATE IT
Originally posted by Al: Jason Troxell-Trust me with two end points viscosity is linear on log paper. I'll explain later-'gotta go