Oil is an essential lubricant in your engine. It lets metal press against metal without damage. For example, it lubricates the pistons as they move up and down in the cylinders.
1 By the time of the Japanese surrender in August 1945, Korea was the second-most industrialized nation in Asia after Japan itself.  But the wartime mobilization of 1937-45 had reintroduced harsh measures to Japanese colonial rule, as Koreans were forced to work in Japanese factories and were sent as soldiers to the front.
HISTORY According to Korean legend, the god-king Tangun founded the Korean nation in BC 2333. By the first century AD, the Korean Peninsula was divided into the kingdoms of Silla, Koguryo, and Paekche. The Silla kingdom unified the peninsula in 668 AD.