I've heard many people say that they decrease diameter on their winter wheels. I can see decreasing width to get more pressure on the roads, but why would you decrease diameter? To me, it seems like increasing diameter for a greater ground clearance is preferred.
Thanks.

 

Smaller wheels, higher profile tires. Same overall size/height/diameter.

You're confusing 'wheels' with the overall package.

Smaller wheel means more tire sidewall means increased pothole compliance.

 

Okay. That makes sense now. Thank you!

 

And don't forget the cost in this decision, since winter tires are softer compound and will wear out faster:

* smaller wheel diameter -> tire with larger sidewall -> usually cheaper
* larger wheel diameter -> tire with low profile sidewall -> more expensive

The higher price could be due to tire construction processes, but could also be simple supply & demand economics. People don't want the small diameter, large sidewall tires, so they become cheaper. However, everyone loves the large diameter low profile tires, hence the higher prices.

Also it appears that low sidewall tires tend to wear out faster than large sidewall ones, which means they will cost even more money long term.

For winter tires you can stick to OEM base Fit size: 175 / 65 / 15 on steel rims.
Steel rims handle potholes & curbs much better than aluminum alloys. Steel will usually bend, but aluminum alloys will crack.

 

what about tpms.
thought about getting a set of dedicated winter tires, but lack knowledge
if tpms is required.
same thoughts for +1 wheel and tire size with good set of performance tires.

thanks

 

TPMS is not required. In the summer my light is on from my summer set of wheels. Having a dedicated set of winter wheels makes a huge improvement in winter performance. Same for summer performance with summer tires. +1 size is fine, it will just require a smaller profile tire.

 

TPMS will be required, especially in the winter since you can't disable the TCS if the TPMS light is on.