Well, it appears, there are differences between all trucks indeed.
For one of my Drivers, I tried to tune up the Sterling 9400 to the max.
One thing I realised, I will have no chance to get an 600 HP Engine for that beast
That will mean, there are 2 cathegories all trucks are sorted to:
Racers
Freighters
I have looked into the Truck Store interface, no Sterling 9400 typ available with 600 HP ^^
Fazit:
Sterling 9400 = Freighter
Argosy (600 HP) = Racer
With that knowledge, it should be more easy for us to give the right Truck to the specific Type of Driver.
Also it can save alot of money from beginning.
The Sterling in good conditions is very cheap ~60.000 to 80.000 Dollar
The Argosy in good conditions is a bit more expensive, but still a cheap Racer.
If I'm wrong, forget my theory
Cheers