Under Pressure / Understanding Diesel Engines
Big rigs. Eighteen wheelers. Semi-trucks. We’ve all heard the terms. We’ve all seen the massive tractor and trailer units on the highway. But ever wonder why nearly every one of these big units runs on diesel?
The reason is quite simple. Diesel engines have more pulling, lugging, and hauling power than their gas-powered counterpart.
Though similar in some regards – both are internal combustion engines – they have some striking differences. The key is how combustion occurs. In a gas engine, air and fuel are mixed and then compressed by the pistons – ignited by a spark plug. The air is compressed and combined with the fuel in a diesel engine. Then, as the air heats when compressed, the air and fuel mixture ignite – not with a spark plug but with a glow plug.
It’s one of the reasons you’ll see big rigs with diesel engines left running in extremely cold conditions. Diesel engines can be difficult to start in cold weather. Again, a diesel engine uses heat and pressure from the piston’s movement to ignite the fuel. The mixture must reach a specific temperature for ignition to occur. In extremely cold conditions, without pre-warming, ignition is less likely. Also, why it’s essential to plug in your personal vehicle with a diesel engine when temperatures drop below 15 degrees Celsius.
As diesel fuel burns more slowly than gasoline, a diesel engine can run at lower RPM (Revolutions Per Minute), reducing engine wear and tear.
The answer to why diesel engines are the preferred choice for big rigs and many commercial vehicles is torque. Diesel engines have more torque, even though they burn less fuel. Diesel engines have higher compression, allowing them to move from a dead stop to highway speed faster than a gas engine. The “power” response is quicker with diesel when stepping on the accelerator, no matter how heavy the vehicle or the load.
More torque, higher compression, better fuel economy and increased pulling power make diesel engines popular for demanding applications. Diesel engines are also favoured in passenger vehicles, predominantly European models. Mercedes-Benz holds the record for longest diesel engine life with one million, four hundred and forty-eight thousand kilometres.
Here at Gearhead Automotive Services, we’re not suggesting that you run out and swap your gas vehicle for a diesel, but if you own a passenger vehicle with a diesel engine, know that we can perform all regular, required service and repairs to ensure years of dependable performance.
Whatever you drive, gas or diesel, foreign or domestic, we’re here to help. We’re Gearhead Automotive Services – your one-stop Red Deer Mechanic. Find us at 7597 Edgar Industrial Drive. Call us at 403-358-5801 or email info@gearheadauto.com