The topic title pretty well explains my question ....thanks for any info in regard to TIME it takes, ROUTE, road conditions, etc

The route depends on what you want to see and do along ehe way.

The big questions is will you be dropping off a car rented in Spain, or Portugal? If Spain, are you willing to pay the steep drop-off fee?

Right. Are you doing this just to get to the airport, and if not, how much time do you have?

If you just want to get to the airport (not a method I would choose, but whatever), then use this site: http://www.viamichelin.com/

thanks! renting car in Portugal, return Lisbon airport to fly out the following morning early...."three day trip to Seville prior, from Algarve. Quickest way , I think only 4 or 5 hours?? have any of you made this trip, Seville to Lisbon airport/,,,, is it freeway/toll.
Seems to be routed back to the Algarve,, but not sure.

There are a couple of different routes possible. Assuming you want to just go directly and not stop to sightsee on the way you should plan on it taking about 6 hours - plus food and potty stops.

Viamichelin.com will show you all of the options.

We did it in reverse - Lisbon to Seville - stopping in Merida on the way to see Roman ruins - but it was a long day.

If the time stated on a route planning map then add a some more time. You may well also need to add time for eats and drinks etc. Do not forget Portugal is in a different time zone to Spain.