my bike out of fuel, where to get juice?

[Speaty]

travel is hell in open world... bike is a must...
I progress in game, and am at 2nd area of the map where I fight a level 13+ monster,

I already have 'garage' and understand the game more and more everyday...

but I notice my bike is running low fuel, I press 'G' to full it, but I don't have the item
so, how to get it?

what 'tree' craft I should unlock to open the item!

thanks

[みさかりん]

Portable mixed fuel can be found on car's trunk all over the map. The other method is mining/siphoning crude barrel oil from an area that has oil indicated by the dark soil or near those mining like structures you see in maps. You siphon crude oil by placing water pumps and process it on a refinery to make portable mixed fuel. Take note that your water pump does not have to be placed on a dark colored soil to mine oil.

[Speaty]

ahaa... nice, I thought I have to unlock something that preduse fuel like carfting ammo and food