What type of cars are considered commercial? Are vans considered commercial vehicle?

It all depends on the state you live in.

Some states deem all vans and pick-up trucks as commercial. That is what they were intended for. Also the tags and plates are more tax revenue to the states. I'd say less than 50% of vans or pick-up trucks are used for commercial reasons. All you have to do is be seen once by the police using the vehicle to haul something if you have passenger plates and you'll get a huge ticket, about 4 foot by 5 foot, and a fine to go with it.