Active Adaptive Shift (AAS) automatically controls the transaxle shift points to best suit the road conditions and driver input. This improves driving feel. The transaxle may switch to AAS mode when driving up and down slopes, cornering, driving at high elevations, or depressing the accelerator pedal quickly while the selector lever is in the D position. Depending on the road and driving conditions/vehicle operations, gear shifting could be delayed or not occur, however, this does not indicate a problem because the AAS mode will maintain the optimum gear position.
Mazda 6 Owners Manual: Scheduled Maintenance (U.S.A., Canada, and Puerto Rico)
Follow Schedule 1 if the vehicle is operated mainly where none of the following
conditions (severe driving conditions) apply.
Repeated short-distance driving
Driving in dusty conditions
Driving with extended use of brakes
Driving in areas where salt or other corrosive materials are used
...
Mazda 6 Owners Manual: Replacing a Wheel
WARNING
Always use wheels of the correct size on your vehicle: Using a wrong-sized
wheel is dangerous. Braking and handling could be affected, leading to loss of control
and an accident.
CAUTION
A wrong-sized wheel may adversely affect:
Tire fit
Wheel and bearing life
Ground clearance ...