What will change tires from 215/45R17 to 195/65R15 do?

I'm considering buying a new car. It comes with the 215/45R17 wheels, but the (lower equiped) have 195/65R15 (same brand, same type, same speed index 87V) - so the manufacturer is ok with the 'downchange'. I'm considering it to reduce the turning circle and reduce gas usage (even manufacturer says 'lower equiped versions' consume less - equipment adds not much weight). How will it affect the driving? Softer/harder ride? Less stability when dry, but less prone to aquaplanning? How will they handle on snow?What will change tires from 215/45R17 to 195/65R15 do?Softer ride, slightly better fuel economy since they weigh less, but you must have your speedometer and odometer corrected or it will throw them both way off. Aquaplaning depends on the tires you are using.