It should use more revs so as not to behave unnaturally. I know that automatic transmission is a difficult thing, but probably just letting the clutch transfer another +250 of power might help.
Higher gears use less from the available rev limit.
I am also aware of the fact, that the M1025 has still multiple different issues:
//- Textures modding,
- Missing hood slot in its inventory
- Attaching/Detaching hood
- The engine's fan isn't animated (spin)
- Vehicle without trunk door has levitating support pistons
- Non-animated use of handbrake//