5W20 versus 5W30

Joined
Jul 14, 2020
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244
Location
VA
Overheard this conversation in a waiting room the other day. Lets use Mobil 1 for an example and lets say it is 20 degrees fahrenheit outside. Would the 5W20 and 5w30 flow the same at start up? I guess the same could be asked of the Mobil 1 AFE line. Does the AFE 0W20 and 0W30 flow the same as well?
 
"Flow" is mostly irrelevant, it is about cranking and resistance to gelling in the vicinity of the oil pump pickup tube at extremely low temperatures.

At the temperature you indicate the winter rating between the two is also irrelevant, but a 20 grade will be thinner since it is a 20 grade, not a 30 grade.
 
0W only really shines when it's like -30 out, the only real benefit to a 0W oil is it should be thin enough to pump in very cold climates without the need for a block heater. In most of the US except maybe a few parts up close to the Canadian border, 0W is widely unnecessary.
 
At 20F I'd take the 5W30. It will work just as well as the 5W20 at 20F, and offer better protection in extreme heat, or if my engine starts to overheat for whatever the reason.
 
Overheard this conversation in a waiting room the other day. Lets use Mobil 1 for an example and lets say it is 20 degrees fahrenheit outside. Would the 5W20 and 5w30 flow the same at start up? I guess the same could be asked of the Mobil 1 AFE line. Does the AFE 0W20 and 0W30 flow the same as well?
Since you mentioned AFE 0W20 and 0W30 here is the viscosity difference between those 2 oils.
AFE.jpg
 
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