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. Engine Valves R&R
Valve stem oil seal alignment
and position is critical. An improperly installed valve stem oil seal may
lead to excessive oil consumption, and increased vehicle emissions.
When replacing multiple valves
simultaneously, mark valves in relation to cylinder/port. Keep al ...