Renting a car in Spain for traveling through Portugal

With what appears quite limited time, I would not mess around with driving.

ALSA Bus
• Santiago de Compostela to Porto
• Lisbon to Seville

High speed Portuguese train
• Porto - Coimbra - Lisbon

If you're only going to those cities, then public transportation is the way to go. Parking and driving in cities can be a pain. If you plan on stopping at small towns or other sights you happen across en route, then get a rental. There are advantages and disadvantages to each mode of transportation.

I don't see you having time to stop in additional places with just two days (minus travel time) for each place. 1-1/2 days is painfully short for Lisbon, in particular.

Thanks everyone... very good points.

Thinking about it, wouldn’t a car be best since will be faster? I don’t want to spend 5-8 hours in buses/ trains... I am bringing a large suitcase also since I will be teaching in Spain for a month before this trip start.., one large suitcase 3 small carry on...

A car may be faster. You can check by comparing the train time on the Deutsche Bahn website to the driving-time estimates on ViaMichelin. VM is thought to be too optimistic, and in any case it does not include time for stops, getting lost, looking for parking, etc. Finding a place to park in the central (historic) areas of the cities you list may not be a simple or inexpensive matter.

Be sure you select a car with adequate luggage space. This is often an issue with European cars. Remember that you must leave nothing visible in your car any time it is parked. And don't wait until you arrive at your parking space to open the trunk and put things in it. Theft from parked cars in tourist districts has been an issue in Europe (and not just in Europe) for decades. Don't be a victim.

Google Maps lists Porto to Lisbon as 2hr 55min by car. This would be a best possible time, then you have time for navigating, parking, fuel and meal stops.

The fastest journey by train from Porto to Lisbon takes just 2hr 35min.

ViaMichelin gives 3 hr. 40 min. for the drive from Porto to Lisbon. I think people generally find ViaMichelin's time estimates more trustworthy, if still optimistic. There have been recent posts finding significant fault with VM's routings, however.

I rushed my reply above as I was about to enter the cinema, hence my ‘best possible’ qualification. Lol

Thank you all so so much for all this imput!!
I will take all this into consideration!
Gracias!

Unless you find a major difference in time between a bus/train and driving yourself, go with public transport. You will spend a lot of time (and money) trying to find parking that can easily offset the time savings of having a car to get between towns.

We are looking at a similar trip and the drop off fee was unbelievable. We are dropping the car in Vigo, Spain and picking up a new one in Coimbra.

Maybe because you were going to drop of in another country? We are renting in Seville, traveling through Portugal and drop in Santiago: both Spain