Pump Jack

This thing is present at:
Trainyard Water Treat Power plant
it effectively triples your low grade fuel once you refine the crude oil pumped from it if you have the time to d oso.

With the recent conversion to diesel and the current yields, 38 diesel is the maximum you can use without overfilling the output (2280 crude / 5 stacks, 6460 LGF / 13 stacks).
Compared to the previous effective yield (after subtracting the value of wood for refining) of ~2.91x, the new effective yield is ~1.15x, which works out to a 12.8x nerf in yield (ouch). But if you have a full load of diesel, you'll still make a tidy profit (about 1.7k LGF or 5.66 diesel profit from a load of 38). As long as nobody ever steals any of it...
Frankly, I think the new yields are a total deal-breaker for pump jacks on PVP servers. It's just not worth the risk for a measly 15% profit. I don't know what FP were thinking.

Takes way too long. Just go barrel mining and get alot more

It can be pretty good if you are willing to leave it on and be away from it. I like to stick some fuel in and then go do other stuff, hit up a couple of monuments then come past on the way back.