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. Tire & Wheel Assembly Rotate & Balance
A statically balanced wheel is
balanced in one plane, around centerline of wheel. This prevents simple
up and down movement relative to centerline of the wheel. A dynamically
balanced wheel is balanced on both sides of hub. This reduces the chance
of wobble off axis. Dynamic b ...