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 Owners Manual. Enhanced Traction System (ETS) Indicator/Warning Light
For vehicles with the
Enhanced Traction
System (ETS), this light
serves as an indicator
and warning light.
This light comes on briefly while the engine is started.
If it does not, have the vehicle serviced by your
dealer/retailer. If the system is working normally the
indicator light then ...