This test was performed by an Austrialian performance car magazine about 4-5 years ago. The engine used for testing was a small block V-8 that was toleranced to use heavier oils, hence most of the formulations tested were 5w-50/15w-50/20w-50/10w-60 grades.
The Mobil 1 products were the same formulations that were available in Europe and other markets at the time.They were not the 'trisynthetic" formulation sold in the US, but were 5w-50 and 0w-40 grades as I recall. They did test RP and Torco amoung others, but not Redline. They also tested the Castrol SLX, 0w-30, which is the GC, 0w-30 ....The S2000, 20w-50 formulation was also an earlier version of this oil and is not the same chemistry they are using today. I know this since I've been testing the S2000 since it came on the market in 1995.
All things being equal, a thinner oil will generate more Hp at the top end, since the pumping losses are less. You would expect thicker oils to provide better wear protection to a degree, so there are no surprises there either. The type of testing done here was really more like Ferrography and not conventional oil analysis, since they were doing particle counts and particle size distribution.
Tooslick
[ February 15, 2004, 08:06 AM: Message edited by: rugerman1 ]