As has been said, this topic was covered a while ago, but , having a vehicle which has a spacesaver, I would strongly suggest that you make sure, yourself, that thhe replacement tyres are actually available for it. The reason for this comment is that Renault provide a spacesaver for which there are NO tyres readily available for it in the UK and it can take 4 weeks to get one from Europe.
Secondly, they are definately not a "Get You Home" solution, they are only to get you to the nearest tyre depot, and preferably not with a fully laden van on the back.
I have changed my spacesaver for a steel full size wheel, as it still fits the wheel well, its just a bit wider, so ground clearance is slightly reduced, as it is stored under the car.
Hope this helps.