3.1 Gasoline

Gasoline has been used to power vehicles since the first automobiles were developed late in the 19th century. Gasoline is produced in oil refineries and is the most popular transportation fuel in the world. In Canada, approximately 38 billion litres of gasoline are sold annually.¹

The bulk of a typical gasoline consists of various hydrocarbons with between 5 and 12 carbon atoms per molecule. Many of these hydrocarbons are considered hazardous substances and are regulated. Unleaded gasoline typically contains at least fifteen hazardous chemicals occurring in various amounts. These include benzene, toluene, naphthalene, trimethylbenzene and about 11 others. Overall, a typical gasoline is predominantly a mixture of paraffins, naphthenes, aromatics and olefins.

Over the years, gasoline formulations have changed as emission requirements and engine designs have evolved: lead has been removed; sulphur reduced; and oxygenates and other chemicals added, to enhance performance and improve emissions. Blending oxygen-bearing compounds such as methyl tertiary-butyl ether (MTBE), ethyl tert-butyl ether (ETBE) and ethanol into gasoline increase oxygen-availability within the fuel. The increased levels of oxygen improve combustion, reducing “smog” by reducing the amount of carbon monoxide and unburned fuel that is present in the exhaust gases from the engine.

Engine technologies have also advanced over the last century as automobile manufacturers, responding to the introduction of regulations, have worked to improve power, reliability and emissions. One of the significant advancements in engine technology has been the addition of increasingly sophisticated computerized engine controls and electronics that enable on-board engine diagnostics and support engine performance and emissions optimization. Up to the late 1980’s, carburetors were the primary devices used to mix gasoline with air in preparation for combustion. In the 1990’s, the engine manufacturers migrated from carbureted engines to multi-port fuel injected engines, as they pursued their goals to decrease emissions, increase durability, and meet the latest requirements set in place by the US EPA.

¹Statistics Canada - Sales of fuel used for motor vehicles, by province and territory 2002-2006