For me, I've filled a Bedrockium Drum with LPG, and already have 11m mb in the second Drum. LOL It's not what I expected to happen, for me to have this amazing excess of power/fuel... but it sure is a nice "problem" to have, where to spend it all.
Hitting a pocket of Heavy Oil at 704mb/cycle with my first attempt at the Drilling Rig was real lucky, I've come to realize... first of all I still haven't found a larger pocket of oil, most are half that size it seems... and second, the Heavy Oil results in an amazing amount of tiny hydrated coal, I ended up processing 40 million mb of Heavy Oil, and turning all those tiny coal dusts into diamonds, meaning all the fuels can go into Bedrockium Drums. I quickly learned the Drums are far better than the massive-sized Railcraft tanks. If I'm filling multiple Bedrockium Drums like this, imagine how many Railcraft tanks I would need? Finding a large source of Heavy Oil was really almost a game-changer, I would claim. Highly recommended.
Of course even without the tiny coal dusts I still could use all my LPG with the Advanced Miner II over a Coal vein and probably have just as many drums, same end result.
I use the LPG Drum to run my Drilling Rig, and I use the Nitro Diesel Drum for my Advanced Miner II. I probably need to consider bumping both up a power tier, at a minimum, altho my willingness to let them run slow and steady for a long time is probably why I have my excess of fuel. It won't take too many tiers before my excess becomes a deficit of course.