Winter tire sizing recommendations

BramwellD

Member
:
2019 Mazda CX9 GT
Hi -

Am picking up my 2019 CX9 GT tomorrow, and am looking for recommendations on winter tire sizes. The original tire size is 255/50/20, but several tire shops I've checked in with have recommended going down to the 17 " wheel (245/70/17 or 255/65/17). Does anyone have experience going all the way down to the 17" and does it cause any problems for you on the driving dynamics?

Thanks!
 
17" might be ok, I'll let someone who has gone down to that size confirm. I think it would be fine as long as there is adequate backspacing to clear the brake calipers. I think the only difference in driving dynamics might be a softer sidewall that has more give when pushing the car in the corners, but I doubt you'd really be pushing it much in the winter. Handling will suffer, but ride comfort will improve. My experience is based on swapping my Sig with 20s for a loaner GS with 18s for a few days.

You can go with either tire size (255/65/17 is a 0.04% variance from OEM, while 245/70/17 is a 1.52% variance), but I would recommend 255/65.

When I bought my winter tires, my installer also suggested buying a smaller rim/tire. If I wasn't planning to buy a new set of summer wheels/tires, I would have gone to 18s or 17s. Instead, I swapped winters onto the OEM 20s, and they will be the dedicated winter wheels. Sold the OEM Ecopias to a friend who happened to be replacing his Ecopias.
 
17, 18, 19, or 20, the choice is yours.
https://www.tirerack.com/snow/Winte...el=CX-9+AWD&autoYear=2017&autoModClar=Touring

The advantage of a smaller diameter wheel while retaining the tire outside diameter within 2% of the original is that the taller sidewall gives more cushioning when slamming over the edge of a pot hole or ridge of ice. I'm running 245/65-17, and they work fine (I have some Kia wheels that I'm reusing, thus the size).

There used to be the thought that narrow tires would cut through the snow better and grip better. That has been disproved.
https://www.continental-tires.com/car/technology/wide-tires
 
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