you are buying 12 cans of Johnsen's Starting Fluid for diesel engines lawn mowers chainsaws 10.7oz 12 Pack The two most common uses for starting fluid are going to be when it?s very cold and gasoline doesn?t want to vaporize, and when you?re bringing a vehicle or engine out of storage. In colder weather, a vehicle with a carburetor will struggle to start. The carburetor uses internal jetting to vaporize fuel from a liquid state to a gas state, and colder gasoline will be harder to vaporize. A vehicle with fuel injection will not have the same issue for vaporization as the higher fuel pressure and fuel injectors will vaporize fuel much better. Using starting fluid to start the engine in a cold state will allow the engine heat to warm the gasoline as it enters the carburetor, and will eventually keep the engine running on its own. The same can be said when a vehicle or engine has been in storage for a period of time. If it has a carburetor, even in warmer temperatures, it may require the engine trying to start to pump fuel from the fuel tank to the carburetor. The engine will turn over with the starter and the battery power, but that combination won?t try to start the vehicle if the battery eventually goes dead. If you have an electric fuel pump in your fuel system