1. Park the vehicle on level ground.
2. Remove the oil level plug and washer.
3. Verify that the oil is near the brim of the plug port.
Specified oil grade API Service GL-4 or GL-5
Specified oil viscosity All-season: SAE 75W-90
Above 10 ° C {50 ° F}: SAE 80W-90

4. Install a new washer and the oil level plug.
Tightening torque 40-58 N·m {4.0-6.0 kgf·m, 29-43 ft·lbf}
Manual transaxle
Transaxle oil replacementMazda 6 Service Manual: Instrument cluster removal/installation
Caution
When replacing the instrument cluster, the configuration procedure must be
performed before removing the instrument cluster. If the configuration procedure
is not performed before removing the instrument cluster, it is possible that the
instrument cluster will not operate normally. ...
Mazda 6 Service Manual: Auto Lock/Unlock Function
WARNING
Do not pull the inner handle on a front door: Pulling the inner handle
on a front door while the vehicle is moving is dangerous. Passengers can fall out
of the vehicle if the door opens accidentally , which could result in death or serious
injury.
When the vehicle speed exceeds 20 ...