Deck 28: Gasoline, Diesel and Other Fuels

Question 1

Vapor lock is caused by fuel that does not vaporize easily in hot weather.

Answer 1

False

Question 2

Technician A says a lean mixture burns faster than a rich mixture. Technician B says advanced ignition timing induces knock. Who is correct?

A)A only
B)B only
C)both A and B
D)neither A nor B

Answer 2

B

Question 3

The diesel fuel's antiknock quality is measured by the cetane rating.

Answer 3

True

Question 4

The octane rating has nothing to do with fuel economy or engine efficiency.

Question 5

Pump gasoline may safely contain up to 10 percent alcohol.

Question 6

LP-gas delivers more power than gasoline.

Question 7

LNG (liquefied natural gas)is not a practical fuel for personal use and is only used in heavy-duty applications.

Question 8

A gasoline engine provides more torque at lower speeds than an electric motor.

Question 9

Octane ratings are being discussed. Technician A says most modern engines are designed to use regular grade gasoline. Technician B says to use high octane gasoline only when an engine was designed to use it. Who is correct?

A)A only
B)B only
C)both A and B
D)neither A nor B

Question 10

Oxygenated fuels tend to have higher CO emissions.

Question 11

Because diesel engines burn less fuel, they also emit less CO₂.

Question 12

The most widely used gasoline oxygenate additive is ethanol (ethyl alcohol).

Question 13

Ethanol decreases CO emissions due to the higher oxygen content of the fuel.

Question 14

Compressed natural gas (CNG)is the cleanest alternative fuel.

Question 15

The octane number is a measure of a fuel's ability to produce power.

Question 16

The ideal air/fuel or stoichiometric ratio for a gasoline engine is approximately _____ pounds of air mixed with 1 pound of gasoline.

A)12 to 13
B)14.1
C)14.7
D)15 to 16

Question 17

All the following are factors that cause knock EXCEPT:

A)hotspots in the cylinder
B)carbon on the pistons
C)forced air into the cylinders
D)decreased compression ratio

Question 18

The higher the octane rating of gasoline, the more the engine will have a tendency to knock.

Question 19

Piezoelectric materials can emit a small amount of voltage when they are struck, squeezed, or exposed to vibration.

Question 20

Biomass fuels are those derived from nonfossil sources and produced from plant or animal
products or wastes.

Question 21

Which of the following is NOT a major factor affecting fuel performance?

A)antiknock quality
B)sulfur content
C)volatility
D)nitrogen content

Question 22

Crude oil is separated into its basic chemical compounds through the process of_____ during which the crude oil is heated to about 1,200°F and vaporized. The different chemical compounds condense at different temperatures as the vapor passes through a cooling tower.

A)osmotic reaction
B)fractional distillation
C)catalytic reduction
D)all answers are correct

Question 23

Diesel engines are being discussed. Technician A says diesel fuel contains less energy than gasoline. Technician B says diesel engines produce more torque than gasoline engines. Who is correct?

A)A only
B)B only
C)both A and B
D)neither A nor B

Question 24

All of the following are aromatic hydrocarbons EXCEPT:

A)benzene
B)xylene
C)kerosene
D)toluene

Question 25

Which of the following statements about P-series fuel is NOT true?

A)It is a blend of natural gas liquids, ethanol, and biomass-derived cosolvents
B)It is rated at 89 to 93 octane
C)Unlike ethanol and methanol, it cannot be mixed with gasoline
D)It produces less CO, HC, and CO₂

Question 26

What is the effect(s)of adding alcohol to gasoline?

A)It reduces the chance of fuel line freeze-up
B)It decreases carbon monoxide emissions
C)Both A and B
D)Neither A nor B

Question 27

Technician A says rich ratios of 15:1 to 16:1 provide the best fuel economy. Technician B says lean mixtures have a ratio below 14.7:1 and provide more power from the engine but greater fuel consumption. Who is correct?

A)A only
B)B only
C)both A and B
D)neither A nor B

Question 28

An engine is being diagnosed for a lean running condition. Technician A checks for air leaks in the intake. Technician B checks for alcohol in the fuel. Who is correct?

A)A only
B)B only
C)both A and B
D)neither A nor B

Question 29

Technician A says a motor converts electrical energy into mechanical energy. Technician B says an engine converts chemical energy into mechanical energy. Who is correct?

A)A only
B)B only
C)both A and B
D)neither A nor B

Question 30

All of these statements about excessive alcohol in gasoline are correct EXCEPT:

A)Alcohol can cause corrosion
B)Alcohol can cause a rich fuel mixture
C)Alcohol can cause drivability concerns
D)Alcohol can plug the fuel filter

Question 31

Technician A says an 87 octane fuel is a blend of 87 percent octane and 13 percent ethanol. Technician B says an 87 octane fuel will experience detonation in a test engine at the same temperatures and pressures as a sample fuel blend of 87 percent isooctane and 13 percent heptane. Who is correct?

A)A only
B)B only
C)both A and B
D)neither A nor B

Question 32

Fuel additives are being discussed. Technician A says adding oxygenates to gasoline increases fuel economy. Technician B says adding 10 percent ethanol to gasoline may boost the octane rating 2.5 to 3 points. Who is correct?

A)A only
B)B only
C)both A and B
D)neither A nor B

Question 33

Methanol can be made from ______.

A)wood
B)coal
C)natural gas
D)All the answers are correct.

Question 34

Technician A says there is less heat energy in high-octane gasoline and, therefore, less power is generated during combustion. Technician B says using a higher-octane gasoline than required will not produce more power unless the engine has a knock sensor that allows the system to adjust ignition timing to take advantage of the higher octane. Who is correct?

A)A only
B)B only
C)both A and B
D)neither A nor B

Question 35

Which of the following is considered natural gas?

A)kerosene
B)propane
C)gasoline
D)diesel fuel

Question 36

All the following are emission-related characteristics of diesel fuel EXCEPT:

A)high sulfur content
B)particulate emissions
C)high carbon dioxide emissions
D)high nitrogen oxide emissions

Question 37

Which of the following are characteristics of burning LP-gas?

A)quicker starting
B)fewer hydrocarbons
C)less carbon monoxide
D)All the answers are correct.

Question 38

Excessive alcohol in the fuel may cause ______.

A)lack of power
B)stalling
C)no starts
D)All the answers are correct.

Question 39

All the following statements are correct EXCEPT:

A)During a Reid vapor test, fuel is heated to 100 degrees Fahrenheit (38 degrees Celsius)
B)Vapor pressure is measured in psi
C)The more volatile a fuel is, the easier it will vaporize
D)Tetraethyl lead is added to gasoline to decrease the vapor pressure

Question 40

Technician A says increasing the Reid vapor pressure (RVP)will help the engine start easier in cold weather. Technician B s ays increasing the RVP will increase the possibility of fuel boiling (vapor lock)in summer driving. Who is correct?

A)A only
B)B only
C)both A and B
D)neither A nor B

Question 41

What chemical is added seasonally to gasoline as an anti-icing agent to prevent fuel line freeze-up in cold weather?

A)benzene
B)xylene
C)isopropyl alcohol
D)MTBE (methyl tertiary butyl ether)

Question 42

Technician A says the biggest disadvantage of using CNG as a fuel is that the large amount space occupied by fuel cylinders limits the driving range of the vehicle. Technician B says bi-fuel vehicles are equipped to store both CNG and gasoline and will run on either.Who is correct?

A)A only
B)B only
C)both A and B
D)neither A nor B

Question 43

Which of the following is NOT an advantage of biodiesel fuel?

A)HC emissions can be reduced by 50 percent
B)PM emissions can be reduced by 47 percent
C)Sulfur emissions can essentially be eliminated
D)It costs less to produce than petroleum-based oil.

Question 44

Most diesel fuel currently available at the pump has a cetane rating of ______.

A)40 to 55
B)75 to 85
C)85 to 100
D)110 to 125

Question 45

An LP [propane]-powered vehicle stores its fuel in pressurized tanks at approximately ______ psi.

A)25
B)200
C)500
D)2,000

Question 46

Technician A says large, low-speed industrial diesels require a high-quality and highly volatile fuel because they cannot tolerate excessive carbon deposits that result from low-volatile fuels. Technician B says the small, high-speed diesel engines found in passenger cars are relatively unaffected by carbon deposits and can run on low-quality fuel. Who is correct?

A)A only
B)B only
C)both A and B
D)neither A nor B

Question 47

Technician A says diesel engines consume less fuel per mile than a gasoline engine of the same size. Technician B says diesel engines provide more torque than a gasoline engine of the same size. Who is correct?

A)A only
B)B only
C)both A and B
D)neither A nor B

Question 48

Methanol is not commonly used as an automotive fuel because it is ______.

A)not resistant to detonation
B)highly corrosive
C)expensive to manufacture
D)all answers are correct

Question 49

The volatility of gasoline affects all the following performance characteristics EXCEPT:

A)cold starting and warmup
B)vapor lock
C)performance at higher altitudes
D)fuel line freeze-up

Question 50

In the past the limit for sulfur content in diesel fuel was 500 ppm [parts per million]. The current standard for low sulfur diesel fuel allows a maximum of _____ of sulfur in the fuel.

A)15 ppm
B)50 ppm
C)100 ppm
D)200 ppm

Question 51

Technician A says Number 1 diesel fuel is the most popular and widely distributed. Technician B says Number 1 diesel fuel is blended with Number 2 to improve starting in cold weather. Who is correct?

A)A only
B)B only
C)both A and B
D)neither A nor B

Question 52

Using gasoline with high levels of sulfur can cause ______.

A)damage to engine bearings
B)exhaust valve pitting
C)rotten egg smell from the exhaust
D)all answers are correct

Question 53

While discussing the reasons why the use of E 85 gasoline is good for consumers: Technician A says it is produced in the United States and can reduce our reliance on foreign oil. Technician B says an engine's fuel consumption is greatly reduced. Who is correct?

A)A only
B)B only
C)both A and B
D)neither A nor B

Question 54

Technician A says blending 10 percent ethanol into gasoline results in an increase of 2.5 to 3 octane points. Technician B says ethanol is highly corrosive and highly toxic. Who is correct?

A)A only
B)B only
C)both A and B
D)neither A nor B

Question 55

Gasoline volatility is being discussed. Technician A says gasoline blended for summer use is more volatile than winter gasoline. Technician B says in high altitude areas, fuels must be blended to have higher volatility.

A)A only
B)B only
C)both A and B
D)neither A nor B

Question 56

How can you identify a flex-fuel vehicle?

A)The fourth digit of the VIN is the letter F.
B)It has a clover leaf symbol on the exterior or interior.
C)The filler neck for the gas tank is 15mm larger.
D)The letters FF after the model designation on the rear body panel.

Question 57

Which statement concerning E85 automotive fuel is false?

A)E85 produces less CO_{2  than gasoline.}
B)E85 produces less emissions than gasoline.
C)E85 keeps the fuel system cleaner than gasoline.
D)E85 is more fuel efficient than gasoline.

Question 58

Which of the following chemicals is commonly added to gasoline to increase its octane rating?

A)Isooctane
B)Heptane
C)Sulfur
D)Ethanol

Question 59

Hydrogen-fueled vehicles are being discussed. Technician A says hydrogen [H₂] can be made from natural gas. Technician B says hydrogen can be made from water. Who is correct?

A)A only
B)B only
C)both A and B
D)neither A nor B

Question 60

If a flex fuel vehicle has half a tank of E85 onboard and the driver then fills the tank up with regular gasoline what will happen?

A)There may be detonation (spark knock)on acceleration
B)The system will run rich
C)The system will run lean
D)The system will automatically adjust and run normally

Question 61

While discussing chemicals that are currently added to refined gasoline in order to boost its octane, Technician A says methylcyclopentienyl manganese tricarbonyl (MMT)is rarely added to gasoline. Technician B says ethanol can be added to lower the octane rating of gasoline. Who is correct?

A)A only
B)B only
C)both A and B
D)neither A nor B

Question 62

Technician A says piezo material is a type of crystal that rapidly shrinks when it is exposed to electrical current. Technician B says piezo material shrinks very slowly when current to it is stopped. Who is correct?

A)A only
B)B only
C)both A and B
D)neither A nor B

Question 63

When the sulfur in fuel is burned, it combines with oxygen to form ____________________.

Question 64

While diagnosing a diesel engine driveability problem: Technician A says that while the scan tool data is similar to that available for a gasoline engine, all diesel engine troubleshooting procedures are unique. Technician B says a cylinder power balance check can be made by checking the resistance of the engine's glow plugs.   Who is correct?

A)A only
B)B only
C)both A and B
D)neither A nor B

Question 65

High octane fuel burns ____________________ than low octane fuel.

Question 66

Technician A says that dedicated vehicles are those designed to use one particular type of fuel. Technician B says that bi-fuel vehicles can operate solely on an alcohol-based fuel or unleaded gasoline, or a mixture of the two, which gives the driver flexibility and convenience when refilling the fuel tank Who is correct?

A)A only
B)B only
C)both A and B
D)neither A nor B

Question 67

The process of splitting methane into hydrogen and carbon is called ___________________.

Question 68

Technician A says white smoke in the exhaust of a diesel engine can be the result of a cylinder misfire in a warm engine. Technician B says blue smoke in the exhaust of a diesel engine can be caused by scored cylinder walls. Who is correct?

A)A only
B)B only
C)both A and B
D)neither A nor B

Question 69

While discussing common rail fuel injection systems: Technician A says the individual injectors are activated by the high pressure present in the fuel rail. Technician B says some late-model CR systems have an intensifier in the injector that allows for an increase in fuel pressure. Who is correct?

A)A only
B)B only
C)both A and B
D)neither A nor B

Question 70

Which of the following statements about hydrogen is NOT true?

A)It costs less  to produce hydrogen than it does to produce gasoline.
B)Hydrogen is normally stored as a liquid or as a compressed gas.
C)Engines running on hydrogen are more efficient then gasoline.
D)Hydrogen is highly flammable and there is risk for an explosion.

Question 71

Crude oil is referred to as a(n) ___________________ fuel because it is produced by the decaying of plants and animals that lived a long time ago.

Question 72

The ___________________ number is a measure of the antiknock [detonation-resistance] quality of a gasoline.

Question 73

____________________ is the lightest and simplest of alcohols.

Question 74

LP-gas is commonly called ____________________.

Question 75

Alcohol weighs _______________ than  gasoline.

Question 76

Ethanol has an octane rating of ___________________.

Question 77

The most common method of measuring fuel volatility is the ____________________ pressure test.

Question 78

A diesel fuel's ignition quality is measured by a ___________________ rating.

Question 79

Technician A says that reformulated gasoline produces a leaner air-fuel mixture. Technician B says that RFG generates more carbon dioxide. Who is correct?

A)A only
B)B only
C)both A and B
D)neither A nor B

Question 80

Technician A says that the use of methanol in internal combustion engines has declined over the years. Technician B says that the use of MTBE as a gasoline additive has declined over the years. Who is correct?

A)A only
B)B only
C)both A and B
D)neither A nor B