i cant remember but do these trucks have pre-programmed operator modes?
Maybe it's set to a slower mode?
Or...
what lindetech said :o)
Alot of times when machines go through the dealership they sometimes do not do a full check on everything, they just do a predelivery check and if everything works they ship it out the door. It could be like lindetech says, the max speed setting could just be set lower than the other machines you're comparing it to.