How Much Do You Know About Diesel Engines?


By: Steven Symes

6 Min Quiz

Image: youtube

About This Quiz

To most people in North America, diesel engines are either something only used in pickup trucks, or they're loud, noisy, and kick out lots of smoke. But How much do you know about them?

Of course, in Europe, Asia, and other markets, diesel engines are popular in cars. With a diesel, you enjoy quite a few big benefits, like better fuel economy, improved reliability, and plenty of torque. It used to be that diesel was cheaper than gasoline, but that's changed in the past several years, thanks to an increase in demand for diesel in the United States and China.

Despite the whole Volkswagen Dieselgate scandal, diesel engines don't look like they're going out of fashion anytime soon. Of course, people who don't know that much about them might be perplexed by that fact. But if you understand how diesels work and why they in many ways boast superiorities, you likely already understand. The fact is that plenty of modern diesels don't spew out excessive emissions in their exhaust, thanks to innovations in catalytic converters, so they're not polluting like crazy. In other words, diesels will continue to be a factor in the vehicle market for some time.

Just how much do you know about oil burners? What makes them work? What are they used in? Test out your knowledge of diesel engines right now!

What is the purpose of glowplugs in a diesel engine?

Too many people think glowplugs work like spark plugs in gasoline-powered engines, but they're not similar at all. Glowplugs heat up the air in the engine's cylinders, making the combustion process easier when you're trying to start up the engine in especially cold weather.


What diesel engine can you get on a 2018 Chevrolet Colorado?

You might be surprised that the pickup truck uses such a small diesel engine, but it boasts impressive performance. Sure, the max 181 horsepower isn't anything to scream about, but the 369 lb.-ft. of torque puts the Colorado well above competitors where it really counts.


What engine was the main focus of the Dieselgate scandal?

While it wasn't the only engine involved in the Dieselgate emissions cheat scandal, the 2.0-liter TDI was the main focus, thanks to the sheer number of them on roads around the world. Ultimately, the scandal cost the Volkswagen Group billions in fines and restitution.


How cold does it need to be in Fahrenheit for diesel fuel to start gelling?

Diesel fuel normally flows without any problems, but when it gets this cold, it gels and starts to clog the tank and fuel filters. As you can probably imagine, that makes starting a diesel engine in super cold temperatures difficult, unless you can safely apply some heat.


Why do diesel engines tend to run at lower RPMs?

Because diesel engines ignite the air/fuel mixture through extreme compression, everything inside the engine, from the connecting rods to the pistons and crankshafts, must be thicker and stronger. That means they're thicker, so it takes more energy to spin them quickly, making it more economical to run the engines at lower RPMs.


What happens to diesel fuel as it enters the combustion chamber?

Atomizing diesel fuel involves breaking it into small droplets, or a fine mist, really. The whole point is so the fuel mixes better with the air in the combustion chamber, which increases efficiency since more of the fuel burns up.


Why are so many diesel engines turbocharged?

Because diesel engines typically run at low RPMs, it's difficult for them to draw enough air into the cylinders. That's where the turbo system comes in, since it crams more air through, smoothing out performance and boosting fuel efficiency.


What is the reason for diesel engines being so popular for trucks?

Not only do diesel engines tend to make way more torque, which is key to pulling big loads or towing heavy trailers, they're in general more durable than gasoline engines, making them perfect for working vehicles that rack up a lot of miles and put up with tons of abuse.


Who invented the diesel engine?

In the late 1800s, Rudolf Diesel was in the Polytechnic High School of Germany when he learned about how inefficient gasoline and steam engines were. He set out to create a more efficient engine, which, of course, was the diesel.


The Cummins R2.8 Turbo Diesel is what kind of an engine?

This crate engine appeals to plenty of enthusiasts who want to put a diesel in their ride. It comes with plenty of peripherals, including the remote oil filter, power steering pump, alternator, and throttle pedal.


What size diesel engine can you get in a 2018 Chevy Cruze?

The turbocharged DOHC inline four-cylinder engine features an aluminum block and cylinder head, plus direct fuel injection. The setup is good for a peak 137 horsepower, plus 240 lb.-ft. of torque, which is pretty impressive for a compact sedan.


What do the connecting rods in a diesel engine connect?

Just like in gasoline engines, diesels have connecting rods that transfer the downward movement of the pistons to the crankshaft, which transforms that energy into a spinning motion.


What liquid specifically helps regulate the temperature of a diesel engine?

Just like with gasoline engines, most modern diesels have a water jacket incorporated into the block, which is passageways for the coolant to flow through. It's true that clean oil can help remove some heat from the engine, but the primary function of oil is to lubricate engine components.


Technically, in a diesel engine, what is it that heats up and ignites the fuel?

As the air and fuel mixture in the cylinder is compressed, it gets to the point that the air molecules rub against each other so much, they heat up. That in turn ignites the fuel, which is what makes a diesel engine work.


How many strokes are in a diesel engine's combustion cycle?

Diesels have the following four strokes for the combustion cycle: intake, compression, combustion, and exhaust. These, of course, happen at different times in the various cylinders, depending on the engine design.


How does the diesel fuel come into the combustion chamber?

Before direct injection became the thing in gasoline engines, diesels already used this design, which is more efficient. That means the fuel doesn't mix with the air until it's sprayed into the combustion chamber.


What kind of diesel engine is available for the 2018 Ford F-150?

For the first time in the history of the F-150, you can get the truck with a diesel engine. With 250 horsepower and 440 lb.-ft. of torque, It can handle up to 11,400 pounds for towing, which is pretty impressive.


How do diesel engines start?

When you turn the key in the ignition, you're not triggering any kind of spark. Instead, fuel sprays into the cylinders under so much pressure that it heats up the air, triggering combustion. This can take a second or two, depending on how cold it is outside.


What kind of diesel did the first engine designed by Rudolph Diesel run on?

Biodiesel, or diesel that's made out of agricultural materials, has often been seen as a fringe movement. It's funny to consider that was the roots of the diesel engine movement, since Rudolf Diesel used a readily available fuel for his design.


What kind of diesel engine can you get on the 2018 Nissan Titan XD?

Nissan really turned a corner in the truck market when it teamed up with legendary diesel engine brand Cummins. This setup in the Titan XD is good for a max 555 lb.-ft. of torque, making the truck appealing to people who need extreme towing or hauling power.


Why do some people call diesel engines "oil burners"?

Technically speaking, diesel fuel is a type of oil, while biodiesel is not. The term "oil burner" is an old one, but it has stuck around for decades, although pretty much only enthusiasts refer to diesels this way.


How often should you change the oil for a diesel engine?

Just like with gasoline-powered engines, diesels require fresh oil to run properly, otherwise you're going to get some metal-on-metal action that could ruin the entire engine. Just how often you should change the oil is recommended in the owner's manual, or you can contact your local dealer's service department for that info.


What special name does Mercedes-Benz use for its modern diesel engines?

Mercedes-Benz has a long history working with diesel, although it landed a really bad reputation in North America ​in the 1980s for diesels that would belch black clouds out the tailpipe. The BlueTEC name is supposed to help transform that image, emphasizing that the new technology doesn't produce excessive emissions.


How many fuel filters do most diesel engines have?

To keep the fuel injectors free of any clogs, you must change out these filters periodically. Some are changed out similar to an oil filter, while others contain a cartridge for an even easier time. You should change the filters per the manufacturer's recommended intervals.


Why do diesel engines typically last longer than gasoline equivalents?

Because diesel engines must endure greater forces, thanks to higher compression necessary for combustion, they're overbuilt compared to gasoline engines. Those sturdier parts last longer, hence the longevity of diesels.


What element does diesel absorb more than gasoline does?

Because diesel has a tendency to absorb water more than gasoline does, most diesel engines have a water separator. As you probably can guess, this device collects water from the fuel, so that water doesn't enter the combustion chambers, where corrosion issues might become a problem.


What component in a diesel engine lets the exhaust gases out of the combustion chamber?

Just like in a gasoline engine, diesels use valves to control the flow of air into the combustion chamber, as well as the release of the exhaust gases after combustion.


What is "rolling coal" with a diesel engine?

Rolling coal is a controversial practice typically popular among certain diesel pickup truck owners. They modify the emissions system so the truck will spew dark clouds of soot out of the tailpipe, mostly to annoy other drivers and look "cool."


What do people usually mix biodiesel with before putting it in their vehicle?

While you could put pure biodiesel in your car or truck, you typically get the best overall performance by mixing it with regular diesel fuel. If you buy biodiesel, the rating like B20 or B60 indicates what percent is biodiesel.


How does the energy created by a diesel engine transfer to the transmission?

Just like with other vehicle engines, the spinning motion from the crankshaft is transferred to the clutch via the flywheel. The clutch acts as that interface between the engine and transmission, which are almost always moving at different speeds.


What does Volkswagen call its modern diesel engines?

TDI stands for turbocharged direct injection, because all modern Volkswagen diesels share that setup. Of course, Volkswagen has shifted from diesels and is moving toward electric cars, thanks to the Dieselgate scandal and its fallout.


What 2018 GM compact SUV can be had with a diesel engine?

Not only can you get the GMC Terrain with a diesel, the Chevy Equinox can be had with the same 1.6-liter turbocharged four-cylinder diesel engine. Like other diesels, it promises amazing fuel economy.


Which diesel engine will Jeep offer on the new Wranglers?

You might already know the 3.0-liter EcoDiesel from the Ram lineup. Not only will it provide great efficiency, the EcoDiesel produces plenty of torque, which is great for off-roading through particularly difficult terrain, like mud.


What kind of catalytic converter is typical with a diesel engine?

Diesel oxidation catalyst (DOC) catalytic converters feature aluminum oxide, platinum, and palladium as the catalysts. They help oxidize hydrocarbons and carbon monoxide by combining with oxygen, creating carbon dioxide and water instead.


What is the name of BMW's diesel 5 Series model sold in Japan?

Many have proclaimed that the BMW 523D is the quietest diesel engine they've ever experienced. Reviewers have also remarked that it's surprisingly refined, not creating any vibrations in the car, and delivering smooth power throughout the RPM range.


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