Cost Per Mile
Gasoline powered engines are quick and fast, but incredibly wasteful when it comes to energy produced versus energy used. Almost half of the energy created by burning gasoline is wasted as heat. In a diesel engine, the heat is repurposed and used, thus limiting the amount of waste generated. As a result, diesel engines, especially modern ones, are about 30% more fuel efficient than gasoline engines. This can mean significant savings, as you don’t have to fill up as often, and typically diesel costs the same or less than gasoline. However, if demand increases for it, then prices will go up, which could mitigate the savings. Additionally, since fewer vehicles require diesel (mostly just semi trucks), not every gas station offers it, so that is a consideration.
A diesel engine doesn’t work the same way as a gasoline engine. In a gas powered car, there are spark plugs and distributors that are used to ignite the fuel. For diesel, this process is done with compressed hot air, eliminating the need for spark plugs and distributors. Diesel engines are also built more sturdily, so they last a lot longer than gas engines (some even going as far as 900,000 miles). However, maintenance costs can still be high, mainly because it requires a specialty mechanic. As long as you stay current with routine checkups, though, it should last you a lot longer than a gas car.
The average car driver in the U.S. only has a car for about six years. Although this is the highest it's ever been, this is still not very long. As such, resale value is critical when buying a new car. Initially, diesel cars cost more, usually several thousand higher than gas cars. However, this translates to a better resale value, since the cars last longer and have a reputation of being well built. While this also means that buying a used diesel will also cost more, you can ultimately recoup more of those costs than with a gas counterpart.
Currently, due to the limited demand for diesel, there are some big drawbacks, mostly cost related. There are also fewer options to choose from when searching for a car. However, as gas prices continue to soar, diesel may become a more mainstream fuel source, meaning that the costs associated with diesel ownership will eventually go down. Thus, you may want to wait until that happens before deciding to switch.