Winter Tire Sizing

[a2k]

Hey all,

Getting a pair of winter tires this year to put on my stock 15" steelies (215/60/15 are the stock all season tires, measured the rim width at 7").

So for the winters, I want to put narrower tires on. So I'd like to put on 195/65/15s, but wondering if they are too narrow?

The Kumho IZens I want fit on the 7" width rims - so no prob with fiting. Also, spedometer diff is 0.7% between the two sizes. The kumho's are rated at 91T.

If 195 are too narrow, then 205/65/15 would be my choice.

soooooo too narrow or ok?

thx!

I personally wouldn't go lower than 205mm on a 7" wheel. Not enough sidewall support with a 195 tire.

[a2k]

Originally posted by mfuller@Oct 23 2004, 02:33 AM
I personally wouldn't go lower than 205mm on a 7" wheel. Not enough sidewall support with a 195 tire.

really? according to 1010tires.com tire comparison:

215/60/15: Sidewall Height: 5.07 in 128.77 mm
195/65/15: Sidewall Height: 4.99 in 126.74 mm

there only seems to be 2 mm decrease in sidewall.

If we look at 215 vs 205s:

215/60/15: Sidewall Height: 5.07 in 128.77 mm
205/65/15: Sidewall Height: 5.24 in 133.09 mm

there is a 4.32 mm increase in sidewall in this scenerio...

so i guess the general rule of thumb is that since the width of the tire is decreasing, the sidewall needs to be increased to compensate for the load?
(kinda like when you get low profile tires, gotta make the tires wider to compensate for the smaller sidewall....)

It doesn't have anything to do with the sidewall height. Increasing the aspect ratio relative to tread width only helps to preserve/closely approximate the rolling diameter of your OEM tire size. The rim must be able to properly support the sidewall of the tire. If you go with a narrow tire on a wide wheel, you end up with a slightly convex transition from the sidewall to the tread, and this can cause very unpredictable handling. Conversely, as aspect ratio gets smaller (low-pro tires), you must increase rim width to compensate.

[a2k]

Totally understand you now! Thanks a lot for the explanation -- makes a lot of sense.

i'll stick with the 205/65/15s then!

thx again.

No problem.

... what kind of winter tires are you getting, or anyone else?

My snows are the same size as my stockers on my 15's, 'cause I'm only running them on the front. Works like a champ.

^ May run snows on only the front, but all winter tire makers strongly recommend running snows on all 4 corners. My back end needs all the help it can get to stay put.

I know, I need a couple more. The back end is pretty quick to run out on me. But as long as you pay attention it isn't too bad.

[Vtolds]

Just get the stock tire size and I would put all 4 winter tires on you would be stupid not to.

[a2k]

im getting the slightly narrower than stock tire so as to plow through the snow easier. and i am for sure getting a set of 4... id hate for my back end spinning out on me cuz my front end grabs the ground so much more..

im debating between a cpl of tires:

- kumho izen kw17s (performance winter)
- kumho izen kw19s (brand new tire)

and possible michelin X-ices.. though im most likely going to stick with the kumhos since they are more in my budget. (blizzaks apparently wear out super fast.. Xices supposedly fix that -- but they are a first gen tire too so who knows)

I don't know how much those cost, but seriously, my Coopers were cheap ($50/ea) and work great. I've run them for two winters now and they barely look used.

[Vtolds]

Thinner tires is a stupid idea you mine as well make your tires out of butter and drive around in a hot skillet. Buy regular stock sized tires all 4 winters.

[mike2002]

wider tires tend to sit on the snow, as thinner ones cut through it... still a 215 tire isn't wide.

i agree, dont just put front snow tires on, oversteer is harder to compensate for than understeer in snow. in understeer you just slow down. if your getting 2, put them on back. you wont be the fastest from the stop light, but you'll be safer going around corners. id get 4, but i bought my car with crappy all seasons that are brand new, look like they'll be good for the snow, but they suck for corners.

[jackal2000]

i dont think i will need winter tires. if it snows here, the whole state gets shut down. i think i heard that NC has like 10 snow plow trucks and they are all out in the western part of the state.

[Vtolds]

The last thing you want is your tires to sink even farther than they normally would you wont wider tires so that your contact path will be wider trust my I live in Vermont we run snow plows 24 hours a day and 7 days a week during the winter. some times we get feet at a time trust me you want wide tires. If you get thinner tires than stock you will most likely end up in a snow bank. Last year my brother was following me in his neon he had new snow tires so did I both stock sizes, his are 1 inch smaller and thinner than mine I was doing corners at 50+ in the snow and I watched him in my rear view mirror slide right out into the other lane while I kept right on my path.

[mike2002]

whatever you do.......dont go wider id stick with stock size a wider tire and your weight is more spread out, so you might just sit on top of packed snow. a thinner tire your weight is in a smaller area, so it will go into the snow a little easier. your not going to notice between 225 and 215 or 225 and 235 i wouldn't think. maybe between 215 and 235 though

maybe your car stuck better because its heavier....or the suspension, different brand snow tires? they're a dozen reasons

[a2k]

discounttire.com:
ok if u do a search @ discounttire.com for winter tires - (2000 Alero GX) it comes back with 195/65/15, 205/65/15 and 215/60/15 tires....

http://www.discounttire.com/dtc/searchWint...rd=15&rc=MIDINT

tirerack.com:
2000 Alero GX winter tire search comes back with:
15" Recommended: 205/65-15
15" Alternate: 215/60-15 (this is stock)

http://www.tirerack.com/snow/WinterPackage...00&autoModClar=

Also from Tirerack.com:

Priorities for sizing winter tires are different:

Select a Narrow Winter Tire for Your Vehicle.
A wide, low profile or large tire has to "plow" a wide path through snow which causes more resistance. The narrower the tire, the easier you can get through snow. We'll help verify sufficient load capacity and the appropriate diameter for your vehicle.

[a2k]

also -- if you ever watch WRC rally on snow, most of the drivers choose narrower tires.

Quoting yotatech forums: (offroad forums

"If you follow WRC or SCCA Pro Rally at all, look at what tires they choose for the wide variety of terrain thay race on. On pavement they use wide, un-treaded tires, more rubber on the road=more grip. In snow they run tiny 4 inch wide pizza cutters with studs. They slice through the snow to get to whatever is below it that might provide grip. In rain they use a medium-wide and heavily grooved tire to do both; cut through the water and put lots of tread on the pavemant below."