tyres

Can a puncture in a run flat tyre be repaired?

Hi, can I change the tyre size from "235/45 R17" down to "16"?

My 2008 BMW 3 Series suffers with tyre noise. Will swapping the runflats for conventional tyres improve things? Is there a quiet tyre you could recommend?

I have just bought a 1998 1.4 Citroen Xsara and it has no handbook with it. I am wondering what the tyre pressure should be for the car? Also, would you know if it would be possible to get a handbook for the car from somewhere?

I've got a 01 Audi A4 1.6 Petrol (newer shape) and spent €620 on four firestone 235 x 45 R17 tyres. However, after only 13,000 miles there is very little life left on them, another 2-3k miles at most. I've really looked after them, had them rotated after about 7k and haven't been spinning wheels or any of that boy racer stuff. One of them (back left at present) is worse than the others alright and is pretty much at the end of its life already. The wear is even through all of the tyres.

Question 1: Is this about the normal for this size wheel? It seems terrible to me.

Question 2: I've heard that some of these big name brands aren't really worth the money; can you recommend a more reasonably priced tyre for what looks like an almost annual expense I'm going to have to budget for?

Thanks