This document provides information on gasoline and fuel systems. It discusses gasoline grades and properties like volatility, octane rating, and oxygenated fuels. Key points include: - Gasoline is a mixture of hydrocarbons refined from crude oil for use as fuel in engines. - Volatility and octane rating affect engine performance and emissions. Proper gasoline grade depends on factors like temperature. - Oxygenated fuels can reduce carbon monoxide emissions by containing oxygen. Ethanol and MTBE are common oxygenates.

9. Figure 15-1 This gasoline testing kit includes an insulated container where water at 100 degrees F is used to heat a container holding a small sample of gasoline. The reading on the pressure gauge is the Reid vapor pressure (RVP).

13. Figure 15-2 Normal combustion is a smooth, controlled burning of the air-fuel mixture.

14. Figure 15-3 Detonation is a secondary ignition of the air-fuel mixture. It is also called spark knock or pinging.

21. Figure 15-4 A typical fuel pump showing regular (87 octane), midgrade (89 octane), and premium (92 octane). These ratings can vary with brand as well as in different parts of the country, especially in high altitude areas where the ratings are lower.

35. Figure 15-5 This fuel tank indicates that the gasoline is blended with 10% ethanol (ethyl alcohol).

36. Figure 15-6 This container holds pure gasoline and water. Notice how the water separates and sinks to the bottom.

44. Figure 15-7 A pump showing E-85 which contains 85.7% ethanol and 15% gasoline. This fuel can be used in flexible fuel vehicles only.

55. Figure 15-8 Many gasoline service stations have signs posted warning customers to place plastic fuel containers on the ground while filling. If placed in a trunk or pickup truck bed equipped with a plastic liner, static electricity could build up during fueling and discharge from the container to the metal nozzle creating a spark and possible explosion. Some service stations have warning signs stating not to use cell phones while fueling to help avoid the possibility of an accidental spark creating a fire hazard.