Mazda CX-9 2018 Owner's Manual page 593

Customer Information and Reporting Safety Defects
Tire Information (U.S.A.)
D
"D" is the tire construction symbol. D indicates "diagonal ply construction".
16
"16" is the wheel rim diameter in inches.
90
"90" is the Load Index. This two-or three-digit number indicates how much weight each tire
can support.
M
"M" is the speed rating. The speed rating denotes the maximum speed for which the use of
the tire is rated.
Letter Rating Speed Rating
M 81 mph
8-31
CX-9_8GC3-EA-17G_Edition1 2017-5-29 10:13:38