MGS V The Phantom Pain: How To Farm 7500 Fuel, 500 Precious Metal, 4000 Minor Metal Every 3 Minutes
Reddit user N7Christian has shared a very useful Metal Gear Solid V: The Phantom Pain tip in case you want to fasten the process of upgrading your Mother Base with some extra in-game credits. According to the tip, you will gain 7500 fuel, 500 precious metal, 4000 minor metal every three minutes, without any particular effort.
Here's how you can do it: read each point of the list below or, if you don't mind any spoiler from the Mission 12, watch the video at the end of this news.
First off you need the Wormhole fulton upgrade
Next, load up Mission 12: Hellbound (I recommend unequipping everything you don't need ie costumes, buddies, weapons etc to save some GMP)
Skip the cutscenes and turn around and go back to where Sahelanthropus was
Take out the 2 guards on patrol and go upstairs to your left where you see the containers
After fultoning all 3 jump down to the Intel file and skip that cutscene
After that's complete go back to the last checkpoint
Now hit Abort mission and go back to the ACC
Done! Now comes the hard part which is waiting for all the materials to be processed. I'd leave the game on in the background while you're at work or at school or whatever it is you do.