[Rich Z]

Been reading a lot of stuff about engine oil lately, and I found this little quote to be right interesting in explaining the difference between mineral (dino) oil and synthetics.

The nitty gritty of oils. Mineral oil is refined and the refining process is pretty good but not perfect. here's how my friend from Redwood oil explained it to me so it was easy to understand. Crude oil has everything in it, from gasoline to diesel to all of the weights of oil and each part is processed out of the whole crude oil. Once a weight of oil has been refined. What they are doing to get the different weights is separating the different sizes of molecules that make-up the thickness of the oil. Oil molecules are like little ball bearings that let metal to metal parts glide on them between a certain clearance. Thin oil has small ball bearing like molecules and thicker oils have larger molecules. Picture a bag of marbles, where you have 100 individual marbles. Now instead of having all of the marbles the exact same size, imagine about 80% of the marbles being 1" in diameter and 10% being 3/4" in size and the remaining 10% being 1 1/8" in diameter. Now lay out all of the marbles on a flat surface and lay a piece of wood over the top of it. What is the board going to be riding on? The small percentage of the largest 1 1/8" marbles that are scattered out under the board. Well, that won't make the board very stable and it won't be riding on the majority of the 1" marbles like it is supposed to be doing until the biggest marbles have been made smaller in size so they ALL can carry the board smoothly and glide it across the surface of the ground. That is very much like refined oil. Refined oil has a high percentage of the correct size molecules, BUT, there is also a percentage of carry-over sizes that are smaller or larger in size as well. They can't refine it perfectly. Your engine bearings are like that piece of plywood, not riding smoothly on ALL of the marbles, only in the largest one's which makes the load surfaces uneven and smaller. Now imagine the same piece of plywood with the same 100 marbles, only this time, they are ALL exactly 1" in size, thus dispersing the load over the entire surface of the plywood and floor. That would be the ideal situation and this is very much like synthetic oil molecules, where the molecules are not refined and sorted-out by size but rather are MADE synthetically to a very specific size which carries more of a load and disperses the load over a greater surface area. That is why synthetic oils work so much better than refined oils. The only problem I have ever found with synthetic oils is if you don't have an oil leak with regular oil, you probably will once you go to synthetic. That stuff just has a way of finding its way out of your engine.

Source: http://www.badasscars.com/index.cfm/...102/prd102.htm