User:OnBeyondZebrax/sandbox/Gasoline

One way to reduce knock is to increase the gasoline's resistance to autoignition, which is expressed by its octane rating. Gasoline in available in several octane ratings. Quality gasoline should be stable almost indefinitely if stored in an airtight container. When gasoline is not stored correctly, gums and solids may be created. The presence of these degradation products makes it harder to start the engine. The formation of these gums is accelerated by copper salts, which can be neutralized by additives called metal deactivators. Energy is obtained from the combustion of gasoline by the conversion of a hydrocarbon to carbon dioxide and water. Gasoline is produced in oil refineries. Roughly 19 gallons of gasoline is derived from a 42 gallon barrel of crude oil. Almost all countries in the world have phased out automotive leaded fuel. Gasoline, as delivered at the pump, also contains additives to reduce internal engine carbon buildups, improve combustion, and to allow easier starting in cold climates. In the EU, 5% ethanol can be added within the common gasoline spec. Most gasoline sold in Sweden has 5-15% ethanol added.

The main concern with gasoline on the environment, aside from the complications of its extraction and refining, is the potential effect on the climate. The chief risks of leaks come not from vehicles, but from gasoline delivery truck accidents and leaks from storage tanks. Because of this risk, most (underground) storage tanks now have extensive measures in place to detect and prevent any such leaks, such as monitoring systems. The material safety data sheet for unleaded gasoline shows at least 15 hazardous chemicals occurring in various amounts. Benzene and many antiknocking additives are carcinogenic.

Huffed gasoline is a common intoxicant that has become epidemic in some poorer communities and indigenous groups in Australia, Canada, New Zealand, and some Pacific Islands. In response, Opal fuel has been developed by the BP Kwinana Refinery in Australia, and contains only 5% aromatics (unlike the usual 25%), which weakens the effects of inhalation.