I would recommend that you look at silicon tyres, e.g.: Toyo's or some other brand that I can't remember at the moment (too much booze). Check out the websites for Toyo's and HANKOOKS!! is the other one!! I remember now!! Silicon impregnated tyres cost a little more, but the benefits far outweigh the cost: better mileage, better wear, better handling: the sidewalls are stiffer without having to go to 16" or some other stupid size. Jap tyres balance far better than Aussie tyres I am sad to say, Bridgestone etc., have not yet got it together yet. Just look at the wear pattern on the Bridgestone "Donuts"!!, The shoulders wear out far before the centers, and I am afraid that mine are unroadworthy even though the centers have still almost full tread depth.
Unfortunately, the Japs have done a lot of research into Aussie tyres and conditions, and of course the results are showing. I just wish that Dunlop or someone similar would get off their collective bums and do something about it. Not that I don't like Japs, but I would just like to buy Australian. ( I ride a Jap motorcycle)
As an aside, it is possible to fit 215's to 6" rims without any problems, although your local tyre person may object, it is not illegal or anything. However, you may gat a bit of sidewall flex.
