Some interesting links about oil:
http://neptune.spacebears.com/cars/stories/oil-life.html
http://search.lycos.com/?src=sf&loc=sem&query=synthetic+oil+study
http://www.nightrider.com/biketech/oiltest1.htm

If you have a link about oil post it here.

Interesting features but beware the last one as the test was carried out in 1994!

Working for an oil company (Mobil) I know the advancements made in lubricant technology within this period of time.

One of the real problems with the kinds of tests usually done, is the lack of random sampling, and sufficient numbers of test engines.

It would be tough to get enough engines randomly selected to test each of the oils, so it excludes some of the value of classical testing, because when there are insufficient numbers of tests, "differences" can sometimes be the result of "chance" variations, and they do not represent "real" differences.

There would need to be selection, at random, of probably 15, at the minimum, more like 30, engines, that would be used to test each oil, so that a test of 10 different oils would require 300 engines.

Plus, this would then only apply to that model of engine. If you wanted to then conduct tests of ten different engines, you'd need a total of 3000.

How about this lineup - HD XL74 and TC88; Suzuki/Kawasaki 800 and Suzuki 90CI; Kaw 1600; Honda VTX 1800 and Gold Wing; Yamaha Venture/Tour Deluxe DOHC V4(I forget the displacement) and V star 650 amd 1100. I'd like to know which of about five different oils actually performed better in each of those. That'd be a pretty tough order to fill, though.

I'd like to see some genuine testing of the type I mentioned above done, and funded by the government, or a non profit, not the oil companies, and after it was over, those results would be what oil companies could advertise.