they are not the same, the maximum speed which Audi gives is always very accurate.
1.4 TDI 90hp
Gear ratio in 1st gear / 2nd gear 3.78 / 2.06
Gear ratio in 3rd gear / 4th gear 1.30 / 0.90
Gear ratio in 5th gear / reverse gear 0.70 / 3.60
Final drive ratio 3.39
1.4 TDI 75hp
Gear ratio in 1st gear / 2nd gear 3.78 / 2.12
Gear ratio in 3rd gear / 4th gear 1.36 / 0.97
Gear ratio in 5th gear / reverse gear 0.76 / 3.60
Final drive ratio 3.39