NEED HELP Getting Correct Wheel Size??
 

I'm from the UK, I have a 06 350z with base wheels. I'm know what wheels I want but want too make sure I don't get anything too big and going to rub. if anything I want too get the same size as I currently have so its a simple swap. The rear tire size on there now is 245/45/R18 and fronts 225/45/R18 does anyone know the width off the wheels ill need to 1 fit those tires or just the stock ones that's on there now ? would be a big help thanks

If you're not going to take the opportunity to improve the car with more rubber, then just keep stock width wheels with stock size tires. Or at least go to the time honored 8.5F/9.5R wheel set up (with offsets in the +25 to +30/stock range) with either the stock size tires or go up to 245/40F and 265/40R tires. These are very conservative sizes and won't rub even if you tried.