Exam 28: Gasoline, Diesel and Other Fuels

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?

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

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?

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?

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?

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?

All the following statements are correct EXCEPT:

What does the term "carbon neutral" mean?

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

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

All the following are factors that cause knock EXCEPT:

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

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

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

What is the difference between E85 fuel and M85 fuel?

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

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?

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

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