Why don't Transformers transform into more than one vehicle?

If their alternate modes are only disguises, then why don't they use more advantageous ones when the moment suits them- why do they seem to be stuck with whatever they first choose as a disguise?Why don't Transformers transform into more than one vehicle?because fans wouldn't know which is which.

easily identifiable with one look.Why don't Transformers transform into more than one vehicle?i'm thinking if they did it too many times their body circuits won't adjust to the so many different vehicles they took the form of. so maybe thats why they don't do it.Why don't Transformers transform into more than one vehicle?They have the ability to scan another form to be able to transform into....but they never do it. Weird....I never thought about it!Why don't Transformers transform into more than one vehicle?
It just a show and dream that really don't work in reality. Like Doctor Who really kill off a race of enemy with sound. lol