MTBE is a common blend stock into gasoline. It is valued both as a source of octane and as an oxygenate to reduce the carbon monoxide emissions fro burning gasoline.

MTBE is made from methanol (usually produced from natural gas) and isobutylene, providing a route for converting natural gas into higher-value gasoline.

MTBE use is encouraged in some markets by gasoline regulations that require a minimum volume of oxygen to reduce carbon monoxide emissions. In this role it competes with ETBE and ethanol.

MTBE use is restricted in some markets over concern about its potential toxicity and its tendency to accumulate in ground water supplies when spilled. This has effectively eliminated its use in the US and Canada.