I grind OD6 too)
If you grind there, you can get 300 000/day, 400 000 with base, quests and arena battles. I farm gold quick just because I level up easily (lvls 1 - 180). Thats why I can get 700 000+ gold/day.
I exchanged my grind level to OD8 when I reached level 188. I wanted to get more money. There you can get 1500 gold/1 fuel.
I'll recommend this build for OD8
And, if your mech is ready to get billions, try 2v2OD8 hard. 1800 gold/ 1 fuel
Theese are mechs can be used:
Try to make as bif phys resistance as you can, and 850+ heat
OR
n
Make 200 regen and also as big phys res as you can.
JUST FARM))))))))
300
Got the Distance Generator