Testing ran to find the issue
I ran some tests between 0.127 and 0.2.18e, using an in-development version of https://sprockettools.github.io/TopGearCalculator.html to obtain expected performance values.
In both cases I used a midwar testbed with a 24L V6 engine, and a vehicle weight between 11.1T and 11.3T.
In 0.127 the vehicle reaches within 2km/h of its expected target of 78km/h
In 0.2.18e the vehicle starts to stall when it shifts into 4th gear, unable to break 45km/h
Version
0.2.18e
Additional context
It's very likely that 0.2.18e is applying a singular value across all eras. Others have reported that the calculator gives incredibly below average values with the interwar era, so it may be that a value from another era (such as earlywar) is being applied universally to everything.
Testing ran to find the issue I ran some tests between 0.127 and 0.2.18e, using an in-development version of https://sprockettools.github.io/TopGearCalculator.html to obtain expected performance values. In both cases I used a midwar testbed with a 24L V6 engine, and a vehicle weight between 11.1T and 11.3T.
In 0.127 the vehicle reaches within 2km/h of its expected target of 78km/h
In 0.2.18e the vehicle starts to stall when it shifts into 4th gear, unable to break 45km/h
Version 0.2.18e
Additional context It's very likely that 0.2.18e is applying a singular value across all eras. Others have reported that the calculator gives incredibly below average values with the interwar era, so it may be that a value from another era (such as earlywar) is being applied universally to everything.