At a minimum, gasoline should meet ASTM specification D 4814 in the United States or CAN/CGSB-3.5 or 3.511 in Canada. Some gasolines contain an octane-enhancing additive called methylcyclopentadienyl manganese tricarbonyl (MMT).
We recommend against the use of gasolines containing MMT. See Additives for additional information.
Gasoline Octane
California FuelChevrolet Cobalt Service & Repair Manual. Cooling System Pressure, Test
Caution: To avoid danger of
being burned, do not remove radiator cap while engine and radiator are still
hot, as fluid and steam can be blown out under pressure.
If radiator cap has contamination,
rinse it with water.
Before using a radiator pressure
...