We'll likely rent a car at some point (Mendoza or Salta) - read this on a US government site:

"U.S. driver's licenses are valid in the capital and the province of Buenos Aires, but Argentine or international licenses are required to drive in the rest of the country"

I think IDL are such a rip off - but do we need to get them?

TIA

I believe that it is misinformation.

We have rented in Salta and in Bariloche with no problems at all. Friends have rented in southern Patagonia with no question of needing anything more than their US driver's license. We had US and French driver's licenses - not International Driver's Licenses. I had done research ahead of our first trip to be sure the Int'l Lic. was not needed. And it was not.

The advantage of the IDL (PIC) is that it is an officially recognized translation of your driver's license for any country which recognizes it.
http://www.iadc-club.com/spanish/clist.asp

Although there are car hire places which will not ask for it, be careful of small print about insurance coverage. It may be required in certain provinces of Argentina and not in others, due to the federal set up of the country. I once found a map but there is no way I am looking for it again!

In my opinion it is a good thing to get, but then I am a belt and braces sort of person.

We were in an accident in the far northwest of Argentina and we were glad that we had the IL, if only for one more piece of authentic documentation to hand the police. The car rental agencies certainly did not ask for it. As Huentetu, I tend to be a bit conservative, but when factored in to the total cost of a trip such as this, the expense is minor for a little piece of mind.

I always travel with an IDL mainly because I would be unhappy handing over my real license to anyone(that said it only costs £5 here in the UK). We booked rental cars several times in Argentina and were never asked to produce it on pick up. We were also pulled over by the police in the north west and they were more interested in seeing the rental agreement. IMHO it is best to have it simply because if you do get involved in an incident then it is best not to give the police any excuse for making an issue of the lack of documentation. The translation does help as few policemen in Argentina would be able to understand in English driving licence just as in England, few would understand a license in Spanish

Not a fan at all of car rental there marks one for theft and shake downs. carrentals.com for info on rental insurance
frequently not always requires IDL for validity. If I
were going to rent which I would not I would get the IDL.
Driver/guides selected with care always work out way cheaper and safer than rental for me.Insurance costs are amazing down there can easily double car cost.