but why do people imagine Honda and other car manufacturers bother to make different sizes of wheel/tyre combinations for same type of cars, it would save them millions to make them the same!!
Still so many 'experts' know better!!
Changes to wheels and tyres are mostly done by car makers for styling, not engineering reasons, the exception is where a much higher powered engine is fitted to a model, a low powered city car like the jazz does not need 185/55 low profile tyres just like they don't need 200mph rated tyres - but they can give the car a 'sportier' look - I can understand why someone would want to fit more readily available = cheaper tyres rather than hunt around and pay through the nose for an oddball 185/55R16 tyre size, and the higher profile tyre will absorb road bumps better.
Most Europeans have to have winter tyres by law between October and April and most choose a slightly narrower profile tyre which are better in snow, and I am sure that they all rush to the garage to have their suspension set-up changed every time
the offset (ET or distance from mounting face to centreline of the wheel rim) will be catered for in the wheel not the car (Honda use 45mm on Jazz, so if you buy offset of this or very close the basic wheel geometry will be the same) check spigot (centre mounting hole size) on Jazz it is 56.0 to 56.1mm depending where you look it up - and if the outside diameter of the wheel and rolling radius are the same what's the problem? With a narrower tyre you are not likely to have the problem of tyre hitting the wheel arch or suspension. On modern cars only the toe-in is adjustable by screwing track rod ends in and out - everything else is fixed, and I am sure Honda do not make different hubs for the cars with185/55 and 175/65 tyres. Where people get into trouble is when they start fitting spacers to make wheelbase wider.
I cannot think of any more extreme change in wheel size than going from a 185/55 tyre to a spacesaver, but car seems to steer OK with one fitted - and as far as I know your insurance is still valid - even though going above 50mph not advisable - and if it was dangerous car makers would supply them (in fact most have stopped doing it - but that is a cost and weight saving exercise).