How do you find the differential ratio? Other drivetrain information

[Peter]

BMW differential ratio identification (take off differential cover and you will see stamped code on a ring gear):

typ 168mm	Small case
H41	3.45
H9	3.64
H1	4.10
H8	4.27
H12	4.44

typ 188mm	Medium case
H25	2.56
H38	2.65
H27	2.79
H33	2.93
H23	3.15
H36	3.23
H34	3.25
H39	3.38
H30	3.46
H24	3.64
H35	3.73
H22	3.91
H21	4.10
H28	4.27
H31	4.45

typ 210mm	Large case
H69	2.81
H53	2.93
H56	3.07
H57	3.15
H64	3.23
H60	3.46
XMG362	3.62
H54	3.64
H52	3.91
G58	4.10