What is the best brand of oil for HEFS 4G18 machine?

4G18 engine . It belongs to the high speed head... It is recommended to use a viscosity that is not too large... And the cylinder bore of this head is small .... It is better to use 5W-30 synthetic engine oil ........ If you are running on highway for a long time, you should use 5W-40 oil ..... Because the engine in a long time at high speed, high temperature conditions, the oil will become thin ....