I'm not too sure but according to the manual, using sae 0w-30 in -20 Celsius temperatures (-4 Fahrenheit), will provide better startup. Where I live it will be -35+ Celsius in the winter. So according to my understanding, the oil is working faster to reach the components with 0w-30. So yes I'm guessing that 5-30 is thicker in that situation than 0w-30