Mazda 6 Service Manual: No.19 excessive shift shock on torque converter clutch (tcc)

No.18 excessive shift shock is felt when upshifting and downshifting

No.20 noise occurs at idle when vehicle is stopped in all positions/ranges

Other materials:

Mazda 6 Service Manual: Recommended Oil
U.S.A. and CANADA Use SAE 0W-20 engine oil. Mazda Genuine Oil is used in your Mazda vehicle. Mazda Genuine 0W-20 Oil is required to achieve optimum fuel economy. For maintenance service, Mazda recommends Mazda Genuine Parts and Castrol® (U.S.A. only). Only use SAE 0W-20 oil “Certified F ...

Mazda 6 Service 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 ...