Danspeed1
Dec 13th, 05, 7:18 PM
I never really thought about the actual label on a bottle of engine oil until now. I have a test coming up and although I think I'm pretty knowledge about oil at this point theres just one question I have that no one has seemed to answer here in school. So I'm hoping that someone here can explain this to me.
Quick Lesson on what I know: Standard SAE Oil is given a number based on its viscosity/weight (thickness) at 212*F. If there is a W after the number (10W,20W,30W) It is measured at 0*F. Now what I don't understand. Multi-viscosity oil. An example 10W-30. Polymers help allow the oil to have different weights at different temperatures. In my mind, 10W-30 oil has the same viscosity properties of a 10 weight oil at 0*F. Now this is what I found,... As the oil warms up, the polymers prevent the oil from thinning. At 212*F, the oil has thinned only as much as the second (higher) viscosity number indicates. Heres the part thats a little unclear to me... "10W-30 weight oil will not thin more than a 30 weight would when hot." Does the oil actually thicken when it becomes hot? If you start with a 10 weight oil when cold (a thin oil),... when the vehicle is warm does the oil actually thicken. In my eyes most fluids thin at higher temeperatures. Or does the oil only thin as much as a straight 30 weight would at 212*F, which would still be thinner then a cold 10 weight??? If we compared a 10 weight oil at 0*F and straight 30 weight at 212*F, which would be thinner? I hope this question is clear,... any help you can give me will help me get a better grade on my next test.
Thanks,
Dan
Quick Lesson on what I know: Standard SAE Oil is given a number based on its viscosity/weight (thickness) at 212*F. If there is a W after the number (10W,20W,30W) It is measured at 0*F. Now what I don't understand. Multi-viscosity oil. An example 10W-30. Polymers help allow the oil to have different weights at different temperatures. In my mind, 10W-30 oil has the same viscosity properties of a 10 weight oil at 0*F. Now this is what I found,... As the oil warms up, the polymers prevent the oil from thinning. At 212*F, the oil has thinned only as much as the second (higher) viscosity number indicates. Heres the part thats a little unclear to me... "10W-30 weight oil will not thin more than a 30 weight would when hot." Does the oil actually thicken when it becomes hot? If you start with a 10 weight oil when cold (a thin oil),... when the vehicle is warm does the oil actually thicken. In my eyes most fluids thin at higher temeperatures. Or does the oil only thin as much as a straight 30 weight would at 212*F, which would still be thinner then a cold 10 weight??? If we compared a 10 weight oil at 0*F and straight 30 weight at 212*F, which would be thinner? I hope this question is clear,... any help you can give me will help me get a better grade on my next test.
Thanks,
Dan