Toyota Highlander Service Manual page 655

Oil viscosity (0W-20 is explained here as an example):
• The 0W in 0W-20 indicates the characteristic of the oil which
allows cold startability. Oils with a lower value before the W allow
for easier starting of the engine in cold weather.
• The 20 in 0W-20 indicates the viscosity characteristic of the oil
when the oil is at high temperature. An oil with a higher viscosity
(one with a higher value) may be better suited if the vehicle is
operated at high speeds, or under extreme load conditions.
How to read oil container label:
The International Lubricant Specification Advisory Committee
(ILSAC) Certification Mark is added to some oil containers to help
you select the oil you should use.
HIGHLANDER_U (OM0E017U)
9-1. Specifications
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