@evan Well, what I mean
If I say "I prefer to travel by train" then I am clearly stating a preference (a desire).
But if I say "My preferred mode of travel is car", that *implies* it is the desired mode of transportation, but I could imagine interpreting that sentence to idiomatically mean "My customary mode of travel is car" without stating a value preference.
I could be wrong about this, but I think there may be an actual quirk of colloquial English here.