Train from Porto to Madrid

Depends on how you define best. You can take a regional train to Vigo and catch a high speed train to Madrid there.

Thank you. By "best" I meant most time efficient.

By "best" I meant most time efficient.

Flying.

By train it will take all day- 0813 from Porto to Vigo a 3 hour 20 minute journey, then 1320 from Vigo for a journey of just over 4 hours, Madrid a 1736. (and you have time to see Vigo in your layover).- 9 hours

The driving distance is given as 366 miles taking 5 1/4 hours, add on a bit for stops and traffic, say 7 hrs.

Plane 1 hr 20 minutes stand to stand + time to and from each airport, check in/security time etc at the airport. By far the cheapest option, but probably not much more than an hour or two time advantage over driving.

Do you want to see the countryside- drive or train.

Most stress free - train.

Best for the environment- train

Cross-border one-way car rental is crazy expensive. This really is best done by air.

Flying would be the fastest option, but the train would be the most efficient use of your time as the time on the train can be used to do other things.