I'm thinking of doing a road trip down to Ushuaia from Buenos aires. I have been looking into it and I've come across a lot of different information. I can't work out whether it would be better to take a couple weeks, or to do it in 4-5 days.

Any tips at all would be cool!

Make sure you have a decent car

I visited Tierra del Fuego. Got to drive from Ushuaia - Tolhuin - to Rio Grande, then crossed the border to Chile (the entire Magellan Strait is Chilean so remember you'll have to go through Chile to get down there) and up to Calafate. It took me 4 days.
So, tips: Reconsider your schedulle and yes make sure to have a heavy decent car. It's not easy to stir under the Summer Patagonian wind!

Rodger,

It takes 35 hours to get to Rio Gallegos by bus, and probably 12 hours more to Ushuaia. If you are driving with the same speed, say, 8 hours a day, 47/8 ~ 6 days and you basically will not be able to see anything but the road.

I took this trip back in 2006 (to Ushuaia and back to BA) and spent about 3 weeks (but I stopped for a day or two in a few places along the way).

I have no idea whatsoever. Please keep us posted on what you do, would be great to hear how you do it.

As someone who has done the drive from Ushuaia to Buenos Aires, I would say give yourself more than 4 to 5 days so you can enjoy the ride. Are you going to drive along the coast or Ruta 40?

I would ask the question: Will I have the opportunity to come this way again? If the answer is in the negative then take as long as you possibly can over it and spend worthwhile amounts of time in different places along the way. Oh - and rent a copy of 'Historias Minimas' before you go!