quote:That is not true. I'm no expert but look at the xw20's out there with great UOA's.
Originally posted by Ray H: All things being equal (and they never are), a lower viscosity oil provides less protection against metal-to-metal contact in marginal, high RPM, heavy-duty operation
quote:Dr. T is correct. A synthetic will not make your engine get to operating temperature more quickly.
Originally posted by Dr. T: I think the opposite is true. Synthetics of the same viscosity generally have lower friction and will hence take somewhat longer to warm up. Likewise, thicker oils will generally warm up faster than thinner ones for the same reason.