S1: 4.27
mk3 XR3i: 4.29
S2: 3.82
mk4 XR3i: 3.84
Diesel and carb 1.6: 3.54
Some auto boxes: 3.33

The small difference 4.29 vs 4.27, and 3.84 vs 3.82 is down to small increase in final drive teeth size increase for the RST models.