Mazda 6 Service Manual: No.12 lack/loss of power-acceleration/cruise

No.11 engine stalls/quits, engine runs rough, misses, buck/jerk, hesitation/stumble, surges

No.13 knocking/pinging-acceleration/cruise

Other materials:

Mazda 6 Service Manual: Fuel Requirements
Vehicles with catalytic converters or oxygen sensors must use ONLY UNLEADED FUEL, which will reduce exhaust emissions and keep spark plug fouling to a minimum. This vehicle will perform best with fuel listed in the table. * U.S. federal law requires that octane ratings be posted on gasoline st ...

Mazda 6 Service Manual: Cruise Control (Some models)
With cruise control, you can set and automatically maintain any speed of more than about 25 km/h (16 mph). WARNING Do not use the cruise control under the following conditions: Using the cruise control under the following conditions is dangerous and could result in loss of vehicle control. ...