Bigger Sport Rims

I bought a new Toyota Vios 1.5G last year. I am thinking of replacing the original 15-inch sport rims with 16-inch sport rims. I prefer to have imported and lighter 16-inch rims. My car's original tyre are Eagle NCT 5 185/55R15.

1. What are the advantages and disadvantages of bigger rims?
2. Any adjustments I need to do with the suspension and brakes if I change to bigger sport rims?
3. What kind or brand of tyres and 16-inch sport rims that I should go for?
4. What is the most suitable tyre size for 16-inch sport rims? I prefer something balanced in terms of comfort and performance.
5. Are there such categories of tyres, eg comfort, comfort-performance. and performance?

Reply:
1. I would say that if the engine performance of the vehicle has not changed, I dont see any advantage in changing. Usually the larger diameter wheels are fitted when there is a subtantial improvement in the engine performance and there is need for traction. Therefore the larger diameter with ultra low-profile wide tyres give the traction without having to change any the gearings.
Larger wheel also mean larger tyre and so there will be an increase in unsprung weight which may mean some adjustment to suspension settings if the weight difference is subtantial. As mentioned, usually larger diameter wheels will go with wider tyres and you will need to check clearance of the tyres in you wheel arches and ensure that you new wheels are with the same offset as the originals. I say this because some tyres shops would recommend offsets in order to clear the wheel arches but this would be result in some odd handling behaviour on uneven roads and in wett conditions.

2. I have no suggestion on tyres or wheel brands, but you should look for wheels that are not too heavy.

3. The equivalent 16" tyres for your car would be 195/45R16. This will keep you within the 3% rule with no need to make any changes to your speedometer gearing.

4. Remember that when one goes for low profile tyres, the tyres pressure needs to be increased and there will be some harshness in the ride which may not be acceptable to some people. There is not much the tyres can do except that the degree of harshness will vary sometimes with the brand of tyre.