People will argue over just about anything. I once overheard a conversation between two guys debating which type of boat was better: diesel-powered or gasoline-powered. In my opinion, each has its advantages, and I’m not here to argue which one is superior. However, one of the men made a claim to support his argument that caught my attention – he said diesel fuel is safer than gasoline. That’s what I want to discuss here.
During the debate, he stated that “it is impossible for a diesel boat to explode, while gas-powered boats explode all the time.” I can’t say I agree with that statement as written, but is there any truth to his claim? The answer is yes – and no. It is true that diesel fuel is far less volatile than gasoline.
Most of us know what would happen if you lit a match and tossed it into a pan of gasoline. Now try the same thing with diesel fuel: the match would simply go out. No burst of flame, no small explosion. Nothing. This is also why diesel engines do not use spark plugs. They rely on compression ignition rather than spark ignition. But why?
Let’s look at some numbers. Specifically, let’s compare the flashpoints of the two fuels. Flashpoint is the temperature at which a fuel produces flammable vapors. Gasoline has a flashpoint of around minus 40 degrees Fahrenheit. This means that even in very cold temperatures, gasoline can burn – or potentially explode – quite easily. Diesel fuel, on the other hand, has a flashpoint above 125 degrees Fahrenheit. At normal ambient temperatures, it tends to remain stable and is far less volatile.
Because of this higher flashpoint, diesel fuel can technically be stored more safely than gasoline. There is a lower risk of explosion due to fumes. However, this does not mean we can be lax in how we handle it. Most fuels still pose health risks, such as skin or eye irritation from contact. Inhaling fumes can also lead to respiratory problems.
We also shouldn’t forget that diesel fuel becomes more dangerous when exposed to heat. If its temperature rises closer to its flashpoint, the risk increases. An overheating engine in a boat can easily raise the temperature in the bilge – where fuel tanks are often located. This can create a chain reaction that ends in disaster.
So should you take the same precautions with diesel-powered boats as you do with gasoline-powered boats? Absolutely. Store fuel properly. Keep the bilge clean. Avoid fuel spills. Perform regular engine checks. Many people believe that because diesel fuel is less volatile than gasoline, there’s no need to run a blower before starting the engine. In fact, some diesel boats don’t even have blowers.
In my opinion, if a boat does have a blower, use it. Even if the risk of fumes is lower, a blower helps keep the bilge area cooler, which is better for both fuel storage and engine health.
Besides, it’s just the flip of a switch. Isn’t that worth a little peace of mind?
