Why would you want to choose a diesel engine over a gas engine? This question is one that many people in Austin, TX are asking, especially with diesel prices tracking consistently above the price of gas in the same market. Why would you want to buy a vehicle with a diesel engine? Are there any advantages to it?
The primary difference between gasoline and diesel engines, as any auto repair professional will tell you, is that gas engines use spark plugs and diesel engines do not. Diesel engines and gas engines are both internal combustion engines, but they differ in how they achieve that combustion. Gas engines achieve combustion through direct ignition, in that a spark lights the fuel vapor. Diesel engines achieve combustion primarily through compression.
- They will burn less fuel than a gas engine doing the same amount of work, mainly due to the the fact that the diesel engine has a higher combustion temperature and greater expansion ratio. Gasoline engines in today’s cars are typically 25 percent efficient (meaning that 25 percent of the fuel energy is converted to mechanical energy) while the right diesel engine will convert more than 30 percent of its fuel energy into usable mechanical energy.
- Diesel engines do not have high-tension electrical ignition system to keep up with, meaning that you have better reliability and better acclimation to climates that have damp environments. Since diesel engines don’t have masses of coils, spark plug wires, etc., that eliminates another source of radio frequency emissions. Radio frequency emissions can interfere with navigation and communication equipment, and these are especially important with marine and aircraft applications.
- Diesel engines can deliver much more of their rated horse power, and do it on a more continuous basis than a gas engine can.
- A diesel engine’s life is usually around two times as long as a gas engine. This higher diesel engine life is due to the higher strength of the components used in diesel engines. Diesel fuel also has a lot better lubrication properties than gas as well and may prevent some common car repair issues seen in gasoline engines.
- Diesel fuel is safer than gasoline in a lot of different situations. Diesel fuel will burn in open air, if you use a wick, it won’t explode. Diesel fuel also will not release the huge amount of flammable vapor that gasoline does. Diesel fuel also has a low vapor pressure, and this is especially great for use in marine applications, where the accumulation of highly explosive fuel-air mixtures is a distinct hazard. Since this is true, diesel engines are also not vulnerable to vapor lock.
- Diesel engines also have a gigantic efficiency advantage over gas engines. With any equal given load, the fuel efficiency (mass burned per energy produced) of a diesel engine is almost always nearly constant. This is where diesel engines really outshine gas engines, which use proportionally higher amounts of fuel with higher power outputs.
- Diesel engines , on average, generate less waste heat (which you really don’t want) in cooling and exhaust.
- In a diesel engine, what is called “boost pressure” is limited only by the strength of the components used in the engine, not “predetonation”, which is the norm in gas engines.
- In diesel engines, carbon monoxide in the exhaust is very low, so diesel engines can be used safely in underground mines.
- Diesel engines can use Biodiesel, which can be made from discarded grease from fast food chains, making a great use of a substance which is normally discarded. Diesel engines thus have a great advantage over gasoline engines, which either have to have some kind of adaptation to run synthetic fuels or else use them as an additive to gasoline.
