Diesel vs Gasoline

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Is diesel still relevant or are gasoline engines the go-to choice?

Read in this article:

The Difference Between Gas and Diesel Engines

Before choosing between diesel or gas, it's useful to understand how each power plant works. While there is a difference between gas and diesel engines, both do the job of converting chemical energy into useful mechanical energy via internal combustion. This involves incoming air mixing with fuel. This mixture is ignited after it is compressed by the cylinders, with the ensuing combustion forcing the movement of the piston and crankshaft, ultimately getting the vehicle to move. This continuous process concludes when the piston returns to its initial position and releases gas via the exhaust system.

It's the igniting of the mixture that differs between a diesel engine and a gas one. Gas-powered power plants utilize spark plugs that create a burst of electricity, thereby igniting the mixture. So, how does a diesel engine work to do this differently? Well, they don't use spark plugs. Instead, they use more extreme compression to result in what is known as compression ignition. In simpler terms, diesels compress the mixture to such an extent that combustion occurs on its own.

So, are diesel cars better or not? It all depends on your specific needs.

Choosing Diesel or Gas
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Gas Engine Pros and Cons

In the diesel vs gas engine battle, the latter option is more common, but there are also a few downsides that you should know about before buying your next ride.

  • Maintenance - Although they might not last as long, routine maintenance is simpler with a gas engine. Service intervals are also longer, so annual maintenance tends to be cheaper.
  • Refinement - While modern diesels are quieter than they once were, a gasoline engine typically emits a less clattery sound which buyers of luxury sedans and SUVs may prefer.
  • Cost - On average, in terms of the purchase price for diesel vs gas vehicles, the same new model will be initially cheaper if motivated by gas. Notably, the price of diesel fuel is also higher.
  • Horsepower - The increased power output of these motors makes them a better choice for quicker acceleration. This explains why diesel-powered sports cars are rare.
  • Longevity - In terms of the diesel vs gasoline durability stakes, the former comes out on top. The typical diesel engine does last longer as it operates at fewer revolutions per minute and has thicker cylinder walls, factors that boost its durability.
  • Fuel Economy - Although less expensive initially, gasoline variants have mpg ratings that are comparatively inferior by over 20 percent in some cases.
  • Towing - These engines don't produce as much torque, making them less suited to lugging heavy loads.
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Igniting of Gas
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Diesel Engine Pros and Cons

While diesel-powered pickups are still quite common, it's more challenging to find compact hatchbacks or luxury sedans with the same kind of powertrain. So, what is in diesel engines' favor and what isn't? We've summarized the key points.

  • Durability - Diesels require far less rpm. They are also constructed using generally tougher components. Due to this, the most reliable diesel engines can last for hundreds of thousands of miles if taken care of.
  • Torque - With a better torque output at low revs, these motors provide effortless passing power and cope better with heavier loads. If this matters to you, then diesel engines are better.
  • Efficiency - One of the biggest advantages of this type of engine is diesel mpg, as you'll use less fuel.
  • Longer range - A direct upside of being more efficient, they'll require fewer visits to the pumps, making longer trips less of a chore. However, the higher diesel fuel cost could negate the extra thriftiness. Whether it's city mpg or highway mpg ratings, the efficiency gains apply to both driving environments.
  • Refinement - Although some modern versions effectively fade into the background at a cruise, they are generally noisier around town and generate more vibration than a motor of another kind.
  • Cost - These vehicles are costlier to purchase initially, while shorter service intervals can make them more expensive to maintain.
  • Fuel - Diesel fuel itself is not only pricier but could be more challenging to find in remote areas. A particularly efficient derivative could balance out higher diesel gas prices.
  • Performance - While well-suited for towing, these power plants aren't as enjoyable in high-performance models.
Diesel Petrol
Diesel Efficiency

The Final Call: Gas or Diesel?

Is diesel better than gas? It all depends on your individual needs. If you travel vast distances, are purchasing a second-hand model with higher mileage, or need a pickup for pulling heavy rigs, then diesel is a logical choice. However, if you are looking to pay less for a new set of wheels, want a high-performance sports car, or prioritize refinement, then a petrol vehicle may be a better bet. Gas is also far more common; in fact, diesel-powered sedans are virtually dead in the USA. Finally, the higher cost of diesel fuel can't be ignored.

Five Diesel-Powered Vehicles You Can Buy in the US

Diesels make the most sense when equipped to a hard-working truck, but there are a few other applications for them. Here are five examples for sale in the US, including some of the best diesel trucks on the market:

  1. Ford F-150 Power Stroke 3.0-liter
  2. Ram 1500 EcoDiesel 3.0-liter V6
  3. Chevrolet Silverado 2500HD 6.6-liter V8 Duramax
  4. Cadillac Escalade 3.0-liter
  5. Chevrolet Tahoe 3.0-liter Duramax

As you can tell, these options are mostly pickups and larger SUVs. Compacts with smaller 4 cylinder diesels are more popular outside of North America.

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FAQs

What will happen if you put diesel in a gas-powered car?

Our advice is simple: avoid this at all costs. However, if the worst does happen, the thicker diesel fuel will immediately begin to do battle with the gas vehicle's fuel system. The fuel pump will initially have trouble moving the denser liquid - mixed with leftover gas - through the system.

The fluid that does reach the engine will likely block up the injectors, which will inevitably lead to seizing. While your vehicle can briefly run on a mixture of the two fuels, you won't get very far. Even worse, putting gasoline in a diesel engine car will cause tremendous damage since gas ignites more quickly.

Why are diesel engines more durable?

A higher-compression motor with increased cylinder pressures, diesels are engineered with stronger components. They also generally have bigger crankshafts and camshafts. This allows for superior lubrication of major components. Finally, the absence of spark plugs and the lower revolutions lead to enhanced longevity.

Why do diesel engines have a bad reputation?

These power plants have an outdated reputation for being noisy, contributing more to pollution levels and, in more recent times, suffered a major reputational blow following the Volkswagen emissions debacle. While they are still less refined than petrol equivalents in some instances, modern iterations are noticeably more hushed in their operation. Diesels are more expensive to buy initially, which has also contributed to their decline.

Do diesels need to be driven hard?

Running on much lower revolutions per minute, diesels actually encourage a more relaxed driving style. They produce their maximum torque without much strain, too, which means that they don't need to be revved that hard for decent progress. These characteristics are ideal for truck owners who may often be hauling heavy loads, but it could be viewed as a negative in a sportier model.

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