Question 1

Although biodiesel is cleaner burning than petroleum diesel, pure biodiesel (B100) requires fuel system modifications on pre-1994 diesel engines.

Accepted Answer

B100 biodiesel has different properties than petroleum diesel which can cause damage to fuel system components in diesel engines manufactured prior to 1994. Therefore, these engines require modifications to safely use pure biodiesel fuel.

Question 2

The term MOST-Likely used to describe an ideal fuel, that produces no emissions other than water and carbon dioxide is:

Accepted Answer

Hydrogen is considered an ideal fuel because when it burns, it reacts with oxygen to produce only water (H2O) as an emission, with no carbon dioxide (CO2) or other pollutants, assuming pure hydrogen is used and complete combustion occurs.

Question 3

The term MOST-Likely used to describe the event where air-fuel mixture self-ignites due to increased pressure in the cylinder is:

Accepted Answer

Detonation is the term used to describe the event where air-fuel mixture self-ignites due to increased pressure in the cylinder. Preignition refers to ignition occurring before the spark plug fires, while dieseling is a form of run-on where the engine continues to run after it has been turned off. Noise is a general term and not specific to this event.

Question 4

Water is an enemy to diesels and must not be allowed to accumulate in the fuel system.

Accepted Answer

Water in the fuel system can cause corrosion and lead to engine damage, so it should be drained regularly and precautions should be taken to prevent water accumulation.

Question 5

Which of the following statements is LEAST-Likely true?

Accepted Answer

LPG (Liquefied Petroleum Gas) is primarily composed of propane and butane, but the most common component is propane, not butane. This makes statement C the least likely to be true compared to the other statements, which are accurate regarding the properties and effects of alcohol fuels, methanol, and their interactions with materials.

Question 6

Diesel fuels contain some paraffin (wax). In very cold weather, the paraffin can separate from the fuel. This is called the ____________________.

Accepted Answer

The answer of Diesel fuels contain some paraffin (wax). In...

Question 7

____________________ is a measure of how easy a fuel evaporates.

Accepted Answer

The answer of ____________________ is a measure of how easy...

Question 8

When the air-fuel mixture is ignited during normal combustion, a ____ travels across the combustion chamber and pushes the piston down in the cylinder.

Accepted Answer

The flame front is the region where the combustion reaction is occurring and is responsible for pushing the piston down in the cylinder during normal combustion. A surge is a sudden, temporary increase in pressure or flow, while a spark is used to initiate combustion in the first place. Run-on refers to an engine that continues to run after the ignition has been turned off.

Question 9

When a gasoline engine continues to run even after the ignition key is turned off, this is called ____________________.

Accepted Answer

The answer of When a gasoline engine continues to run...

Question 10

A car's ____________________ on the highway is a symptom of a lean condition.

Accepted Answer

The answer of A car's ____________________ on the highway is...

Question 11

Gasoline can be refined so it will not knock as easily. This fuel has a high ____ value.

Accepted Answer

Octane rating is a measure of a fuel's ability to resist "knocking" or "pinging" during combustion, caused by the air/fuel mixture detonating prematurely in the engine. Gasoline with a high octane rating can handle higher compression before igniting, leading to smoother and more efficient combustion in high-performance engines.

Question 12

The ____________________ of a diesel fuel describes how easily the fuel will ignite.

Accepted Answer

The answer of The ____________________ of a diesel fuel describes...

Question 13

While having a discussion, Technician A says that carbonaceous deposits are caused when oil and heat come together. Technician B says that carbonaceous deposits are from fuel. Who is correct?

Accepted Answer

The answer of While having a discussion, Technician A says...

Question 14

Unlike preignition, detonation does not produce a knocking sound, so the impending damage is not apparent until it is too late.

Accepted Answer

Unlike preignition, detonation produces a knocking sound, which is an audible indication of impending damage.

Question 15

While having a discussion, Technician A says that the noise from spark knock is caused by the vibration of the combustion chamber walls. Technician B says that it is caused by low volatility. Who is correct?

Accepted Answer

Technician A is correct. The noise from spark knock is caused by the vibration of the combustion chamber walls due to the rapid and uneven burning of fuel in the mixture. Technician B is incorrect as low volatility does not cause spark knock.

Question 16

Crude oil is a variable combination of large and small hydrocarbons together with petroleum gas, hydrogen sulfide, and water.

Accepted Answer

Crude oil consists of a complex mixture of hydrocarbons (both large and small), as well as other compounds such as petroleum gas, hydrogen sulfide, and water.

Question 17

Which of the following statements is LEAST Likely true?

Accepted Answer

Diesels typically have a larger capacity oil pan to accommodate the increased oil volume needed for cooling and lubrication due to their higher compression ratios and operating conditions.

Question 18

With gasoline octane ratings, the lower the octane number, the more resistant the fuel is to knocking.

Accepted Answer

The higher the octane number, the more resistant the fuel is to knocking.

Question 19

All of the following statements are true EXCEPT:

Accepted Answer

Diesel engines have a high compression ratio, which is one of the reasons they are more efficient and have more torque than gasoline engines.

Question 20

All of the following statements are true EXCEPT:

Accepted Answer

LPG does not settle out as a liquid in the intake manifold because it is a vapor at normal operating temperatures and pressures.

Quiz 39: Petroleum Fuels and Alternative Fuel Technologies

Although biodiesel is cleaner burning than petroleum diesel, pure biodiesel (B100) requires fuel system modifications on pre-1994 diesel engines.

The term MOST-Likely used to describe an ideal fuel, that produces no emissions other than water and carbon dioxide is:

The term MOST-Likely used to describe the event where air-fuel mixture self-ignites due to increased pressure in the cylinder is:

Water is an enemy to diesels and must not be allowed to accumulate in the fuel system.

Which of the following statements is LEAST-Likely true?

Diesel fuels contain some paraffin (wax). In very cold weather, the paraffin can separate from the fuel. This is called the ____________________.

____________________ is a measure of how easy a fuel evaporates.

When the air-fuel mixture is ignited during normal combustion, a ____ travels across the combustion chamber and pushes the piston down in the cylinder.

When a gasoline engine continues to run even after the ignition key is turned off, this is called ____________________.

A car's ____________________ on the highway is a symptom of a lean condition.

Gasoline can be refined so it will not knock as easily. This fuel has a high ____ value.

The ____________________ of a diesel fuel describes how easily the fuel will ignite.

While having a discussion, Technician A says that carbonaceous deposits are caused when oil and heat come together. Technician B says that carbonaceous deposits are from fuel. Who is correct?

Unlike preignition, detonation does not produce a knocking sound, so the impending damage is not apparent until it is too late.

While having a discussion, Technician A says that the noise from spark knock is caused by the vibration of the combustion chamber walls. Technician B says that it is caused by low volatility. Who is correct?

Crude oil is a variable combination of large and small hydrocarbons together with petroleum gas, hydrogen sulfide, and water.

Which of the following statements is LEAST Likely true?

With gasoline octane ratings, the lower the octane number, the more resistant the fuel is to knocking.

All of the following statements are true EXCEPT:

All of the following statements are true EXCEPT: