It probably means 70 degrees noth and 30 degrees west.
The island located at 70N 40W is called Jan Mayen. It is a remote volcanic island in the Arctic Ocean, situated between Greenland and Norway. Jan Mayen is known for its harsh climate and unique wildlife.
Greenland
The coordinates 70N 20E point to Finland, a country located in Northern Europe. Finland shares borders with Sweden, Norway, and Russia.
30 W
Russia.
The GCF of 30w and 75w is 15w.
30w, 10-30w or 10-40w
5w-30w 10w-30w in areas like Phoenix, AZ
I would not recommend it, stick with the straight 30W.
Use 30w synthetic or 10w30 synthetic. 30w is preferred.
A little after 1976
The GCF is 10w.