Just murder the sea pickles and get so much oil that America will want to know your location

(Island, Mobile) I tend to get my oil from oily rocks up in the north, snowy, area on the very west side where there are icy islands in the water. The oily rocks are all over the icy islands! Hope this was helpful :)

to get oil over time, tame a dung beetle and put poop in its inventory. it'll turn it into oil as well as compost, and you'll get better results depending on the size of the poop.

To make gasoline, put oil and hide into a forge

There are Quite a bit of oil veins on Fjordur, also the oil fields in the volcano island has a lot of oil rocks, otherwise look in ocean or get a Tuso. Up if helpful!

Basilosaures gives up to 1500 oil with better Rates

America wants to know your location.

Tek creatures can drop oil, electronics, AND metal. Tame a breeding pair of Tek parasaurs and kill their babies

if you can’t find a critter that drops oil, i found quite a lot of oil rocks in the northern region (mobile, island map), around the shore. be weary of wolves and argies. rexes too, but typically they’re preoccupied with mammoths or rhinos. hope this helped!