If two cars have identical features engine size and power then why do the two makes

[Man]

gear the cars differently? The gear sizes are about the same but one the rpms sit 2500rpm in 3rd the other rpms sit at 2000rpm and in 4th

So on the 2000rpm car you have to be in 4th while crusing around 37 and other you can stay in 3rd.
2000rpm one has higher axle ratio but lower gear and the 2500rpm one has lower axle ratio but bigger gears but the 2000 rpm one les you shift to 4th and drop rpms by 700rpm at avarage town speed.

 

[magicmboy]

The higher the gear, the higher the RPM and the lower the torque.