Does this sound about right?

[Jbird]

I am going to get winter tires for my newish Toyota Corolla, because the stock tires are low profile sporty tires that don't do real well in heavy rain. So I doubt they'd do good in snow.

18", 225/40

Anyways, the guy at the tire shop said I could do a 16" wheel with /50 sidewall for a winter wheel/tire set up and it would be approximately the same.

Does that sound correct?

 

[Bob411]

If the rim size is the same, the math is real simple. With different rim sizes, I have no clue.

 

[mongooz]

are you saying that you are going from an 18" rim to a 16" rim??
if so, it will change your overall final gear ratio. it will be like suddenly having 4:56 gears (if we were talking about rear drive cars)
you'd have to buy a whole other set of rims. you can't put 16" tires on 18" rims.
i don't know if you want to do that.
just sayin'

 

[jelloman]

225/40R18 diameter =25.1"

225/50R16 diameter=24.9"

2/10 of an inch less rotational diameter is not significant enough to make a difference in how the car drives and handles... it's also going to have only a small impact on your speedometer readings...

If you want to invest in a complete set of rims and tires for winter use the rim substitution should be fine in this instance...

 

[jrockbridge]

I would not know. I’d have to trust the tire guy in that instance.

Why don’t you trust your tire guy? What did he do? Is he an ex-convict or something? Does he have tacky tattoos that bother you? Does he use ignorant language when he speaks? Does he have a metal plate in his head?

In all seriousness, I do my research and make my own decisions on tires. I don’t go with recommendations from people at tire stores. If they tell me there’s a problem with my ideas, I’ll certainly listen and take their opinions under consideration.

Once, I asked a tire shop to recommend a good set of replacement rims for a car. They sold me a set of rims that needed center rings to properly fit my car. They installed them without the center rings. Driving the car felt like I was 4 wheeling over rocks. I brought the car back, made them take the rims back, mount the tires on the old rims and give me a full refund. The manager tried to argue about it at first but I reminded him that I’d been a loyal customer for years and I had relied on their recommendation and “expertise.” So, he caved.

 

[DinoMikeSr]

are you saying that you are going from an 18" rim to a 16" rim??
if so, it will change your overall final gear ratio. it will be like suddenly having 4:56 gears (if we were talking about rear drive cars)
you'd have to buy a whole other set of rims. you can't put 16" tires on 18" rims.
i don't know if you want to do that.
just sayin'

I think he’s looking at a smaller rim but not a low profile tire. In the end the outer diameter will be the same. It won’t handle
as well in turns but the ride should improve and deeper tread will enhance snow and rain handling. .