Ask the Fuel Expert

You might not think diesel smells great but the folks at Diesel Jeans are hoping you’ll like their newest fragrance called Diesel: Fuel for Life. No, I’m not hoping someone will buy it for me for Christmas, I mention it because the name raises interesting questions about how much longer industry can expect to use diesel, what will replace it and when. But let’s start with where diesel came from.

The diesel engine and the fuel it uses were named for its creator. German inventor Rudolf Christian Karl Diesel, who unveiled his first internal combustion engine at the Paris World’s Fair in 1892. And when he demonstrated the engine, he ran it on peanut oil and forecast that vegetable oil would be the automotive world’s main energy source.

However, his prophesy was not to come true for 116 years, when the price of crude oil rose to levels high enough to justify diesel production from non-petroleum sources. So, what exactly is diesel fuel and is it any better – or worse – than gasoline?

Diesel fuel is similar to gasoline and is refined from crude oil. The bulk of the diesel fuel purchased around the world is refined from petroleum, and is referred to as petro-diesel and fuel produced from vegetable and animal fat is typically called bio-diesel.

The difference between diesel and gasoline starts at the refining process. Diesel is considered a heavier fuel than gasoline and diesel fuel is easier to refine than gasoline as well as it packing more energy.

Engines that run on diesel fuel are a bit different than typical gasoline engines and have no need for spark plugs. They instead rely on high engine temperatures and high pressures at the end of the compression stroke to ignite the fuel and are referred to as “compression ignition engines”.

Each gallon of diesel packs more energy than a gallon of gasoline and diesel engines are much more fuel-efficient. Diesel engines typically return 20%-40% better fuel economy than comparable gasoline engines, and many diesel-powered cars are able to deliver gas/electric hybrid-like fuel economy numbers. With recent technology modern diesel engines are as clean, if not cleaner, than most modern gasoline engines.

Diesel engines may not boast high horsepower numbers, but they pack plenty of torque -- especially at lower engine speeds. Horsepower numbers sound nice, but torque is what actually moves the vehicle. Diesel engines typically generate more torque than comparable gasoline motors, which makes diesel engines ideal for transport, power generation and other heavy industries uses.

Price is the motivating factor in deciding the choice we make in purchasing fuel and by extension, when buying cars. Petro-diesel is still the most economical way to power trucks and heavy industrial engines and despite fluctuation in the cost to fill your tank, diesel will remain industry’s fuel of choice. The only thing that will change this is if the price becomes so high that a viable alternative to diesel fuel take its place. But could this happen?

Of course it could happen and it certainly will happen as oil becomes both scarcer and more expensive. However, for a new fuel to displace diesel, it would have to have the raw resources, production scale and distribution all at a price lower than diesel. Even at its height, biodiesel could not manage this. And there’s also the challenge of having to out-muscle the entire oil industry and every person whose jobs depends on it

One alternative is to buy Diesel’s new eau de toilette called “Diesel Fuel for Life” at $50 for a 75-ml bottle. The ad copy suggests it might start her engine but it won’t run your truck. The bottle also reminds us to “use with caution” – probably good advice for both types for both types of diesel.

Bob van der Valk is a leading fuel price analyst on the US West Coast, is regularly interviewed in mainstream media (ABC, NBC, Fox etc.)

Bob van der Valk can be reached at Bvan@4Refuel.com