The most common oxygenates are:
- Methanol - Produced from natural gas or coal
- MTBE - Made from methanol and butylene
- Ethanol - Made from fermenting agricultural products
- ETBE - Made from ethanol and butylene
In many countries, renewable oxygenates such as ethanol are mandated as part of renewable fuel standards.
Also, under the right market conditions, refiners may blend some oxygenates on a purely economic basis as they tend to have relatively high octane levels.