看这一句 The reason is that warm oil has a lower viscosity and therefore flows better than cold oil.
(补充前面说的 The viscosity of an oil is its resistance to flow. In the case of multi-grade engine oil, the oil is designed to have lower viscosity at cold temperatures and higher viscosity at high temperatures. )-- 似乎印证了 coorslight969 前面的观点。
估计应该说是相对稠度吧。
你们这些大活人,居然被几个破计算机耍得团团转。