Hi friend! I was just searching for something along the lines of Max Overwatch as well. All I'm curious about is how to earn fuel if you can no longer rank up once your level 50? But back to your question.... The max percentage for fuel increase and body repair increase is 80%. And the max decreases is 20% for both. But as for ammo up and ammo decreases, there are 4 different ranks for those that you'll eventually unlock by using it more an more. You can see how far you've come with the progression button. You'll notice 4 squares underneath ammo. Hope that helps. Also for you and anyone who likes to help "NOT hinder" his friends, you can add me on origin as "Djmightymizz" ! 🙂