Diesel cars are noisy. Gasoline vehicles are quiet. Diesel used cars leave behind a trail of black smoke.Used Gasoline vehicles emit clean white fumes instead. Aren’t these the differences that we have always heard about between diesel and gasoline cars and almost by instinct, we went towards gasoline cars, completely ignoring the diesel vehicles? Well, there was indeed a time in the US auto industry when diesel cars suffered from a seriously bad reputation but all that has changed with fortunate contributions from modern technology. No longer are diesel cars noisy or emit pitch-black fumes. Instead, the major difference with its gasoline counterpart lies in a more subtle region.
What is the major difference between diesel and gasoline used cars?
Both diesel and gasoline are fuels that ultimately reach the engine of the car to ignite and drive the wheels of the vehicle. The way they are ignited is where the gasoline engines diverge from the diesel ones. In gasoline engines, the fuel is mixed with air and the combination enters the engine’s cylinder during the downward movement of the piston. This mixture is then compressed by the upward movement of that same piston. When compressed, a spark plug ignites the air-gasoline mixture causing a small explosion that drives down the piston again. And the piston comes back up again releasing the accumulated fumes and clearing the chamber for another cycle.
So, overall, a piston completes 4 strokes by 2 upward and 2 downward movements which work to rotate the crankshaft attached to the piston. A V4 engine will have 4 such cylinders with 4 pistons in each and the cycle happens equally in all 4 cylinders. These same procedures happen in diesel engines as well. But instead of igniting the fuel with a spark plug during the compression cycle of the air-fuel mixture, the diesel-air mixture ignites spontaneously on its own being compressed. The explosion happens and the crankshaft rotates.
Thus, as evident, the major difference lies in the presence/absence of the spark plug. While gasoline engine in used cars requires that extra electric circuitry to ignite the air-fuel mixture, diesel engines do not have such requirements. Take this pointer out and modern diesel and gasoline engines function almost the same way. Yet, there are a few non-technical differences that exist owing to the fuel type and engine construction.
Other differences between diesel and gasoline cars
- Diesel cars return better EPA
This is due to the nature of the fuel. Diesel is thick and syrupy while gasoline is thin and runny. Obviously, the density of the former is greater than the latter and packs more energy per unit. Diesel cars are thus known to return EPA figures in the high 30s or low 40s easily while gasoline cars struggle to reach the mid-30s at times.
- Diesel cars are sturdier in construction
As the ignition process involves creating the explosion merely by compression, the engine has to bear a lot of shock in every cycle. This compels the engines to be sturdier in construction and hence tend to be more reliable than their gasoline counterparts. But a thick structure also adds a bit of weight to the engine which may affect the fuel efficiency at times.
- Diesel cars have more torque
Torque is the turning power of the engine while horsepower is the overall punch that the vehicle can pack. Thus, for SUVs and trucks, diesel engines are a nice fit since they are typically used to haul a load. But for sports cars or sedans where often horsepower is more of a preference, gasoline is still the winner. It returns better HP than diesel hands down.
Take your pick
When it comes to buying modern used cars, you really do not need to worry about the difference between diesel and gasoline cars. Right now, both types perform nearly the same. Visit a top used car dealership like family auto group which has a large inventory and select the car you like the best.