Just seen an interesting piece on Qashqia tyre wear. If you want to keep your 19 inch wheels the look at www.nankangtyre.co.uk/. They are only one of three companies making this size and rating of tyre. I have them on a +2 and am very impressed.

Interestingly when in discussion with Nissan they did agree that the speed rating of the tyres as supplied was very safe and tyres with a lower speed rating could be used if they meet the legal requirements. They do not specify them as they have tested them.