[robogeek753]

Just to echo what everyone else is saying, to me (and I know how the "we need to shave off just .1 lbs. AHHHHHH) you should always put all four tanks on (you never, EVER, want to run out of air, its really not very fun, so you should play it safe) and if you're going to be using the pneumatics for, say something like scoring, you need to put the compressor on too; because that air will be gone really fast (note last comment about running out of air)