B Driving Licence
The B Driving Licence, which is what most have, currently allows you to drive a "turismo" up to 9 seats with a maximum weight of 3500 kg.
New proposals by the EU, which would affect drivers in Spain, would increase this to 4.250kg. This would mean you could drive a camper type vehicle with no additional licence and even things like the Hummer SUV would no longer require a truck licence to drive it.
Mainly brought about by the extra weight in EV SUV but would also mean the ICE campervans and motorhomes could be driven on your B licence.
Also note that the Spanish government has approved a fine of up to 500 euro if you do not carry your driving licence in the vehicle with you.