I used about half a pack of these mats to soak up the diesel from my boat's bilge before activating the bilge pump and pouring the diesel overboard. When I finished there was only some water left that I had in the cargo hold before the diesel leak. Very impressed with these mats! I have a few under the engine bay. I love that they are perforated (tear very easily), are white so easily show oil or whatever, and you can even trim them to fit. Very satisfied. Just ordered a new refill pack!