Minus Sizing?

[Rogue Two]

Can anyone help explain "minus sizing" and how that might affect my car? I've been contemplating snow tires for the winter and I found this on the Tire Rack website about using a smaller tire for the winter to give you better traction, etc. This is the first time I've heard of this and they don't really go into it much. Anyone have any additional thoughts, facts, etc.?

[andysinnh]

First, you have to understand "plus sizing" to then understand "minus sizing".

Plus-sizing is a way to increase the tire width or wheel size WITHOUT increasing the overall diameter of the tire. You do this typically when you want better handling/cornering (more rubber on the road), or when you want to upgrade your wheels to a larger size. You play games with going from like a 205-65R15 to a 225-55R15, or a 205-65R15 to a 205-60R16, to show two examples. The first number is the tire width in MM, the second number is the profile, or a percentage of tire width to tire thickness (between road and rim). So when you want more width, you decrease the percentage of width vs. thickness (or lower profile).

Minus-sizing is the opposite - a thinner tire with more tire thickness. Why do you do this? Because in the winter, a thinner tire cuts thru the snow/slush better than a thicker/wider one does. So, if you go with a 205 width tire in the summer, you'd want a 195 width tire in the winter for better snow-cutting traction. In order to keep the overall tire height the same, you increase the percentage of tire width vs thickness, or a higher-profile tire (more rubber between road and rim). Sometimes if you have a 16" summer rim you'd go with a 15" winter rim and a higher profile tire to get better performance.

So - long story short - minus-sizing gets you a thinner tire for the winter that won't throw your speedometer off. If you want to play it safe, just get the same size winter tire/wheel as you have for the summer. It'll work fine in 90 percent of the cases.

andy (closet tire fanatic)

[BenjiBoy650]

Yup, what he said. Thinner tires cut through rain/snow/sleet much better. You put more pounds on a smaller contact patch = more traction. When it's dry it's different because the amount of traction is limited by how much rubber you put to the road.

[Accordca]

Hey guys,

I'm new to this site. I bought my accord last February and am about to buy some winter tires. I am contemplating going from 16 inch rims to 15 for the simple fact that it saves me several hundred dollars. I have had one dealer tell me it's ok, while another has told me it's not. So, I'm pretty confused. Does anyone know if it's ok to go from 16 to 15's, and if not, why not???

For a reference, I have a 2005 Accord EX-L with 16 inch mags. I would be buying 15 inch steel rims for winter.

thanks.

[andysinnh]

The accord is built with 15" wheels as a minimum diameter - I have an '05 LX that has stock 15" steel wheels. If you go to tirerack.com, they actually recommend the 205-65R15 winter package - gives you more rubber between the wheel and the road, and the tires are much less expensive in that size.

I'm running the OEM steel wheels with snows this winter - they fit fine.

andy

[Accordca]

Thanks Andy,

Just saw the thing about minus sizing at Tiretrack... seems simple enough and hope it applied to the 05 Accord. When I searched for the accord EX on Tiretrack, it said it recommended 16 inchers.... but I think I would be safe with 15's.

[andysinnh]

The only difference between the Accord LX and EX for '03-05 is that the rear wheels have disc brakes, and I can't imagine that the 15" wheels wouldn't fit - the front brakes are the same.....

Unless someone has info to the contrary...

andy

[Accordca]

I figured there wouldn't be a problem, but I got contrasting information from 2 dealers and Honda itself didn't have an answer for me so that was great help. The rear disc brakes are much smaller than the front ones, so I don't see that being an issue. The only think I am worried about is making sure the calipers have enough space so they don't get damaged.

I think I have settled on 15 inchers, unless, like you said, anyone else know something to the contrary.

[andysinnh]

I poked around a bit, and it "looks" like the V6 sedans have different brakes (at least front) because they don't even list a 15" option for the EX V6, whereas the EX I4 does show the 15" as an option. Hmmmmmm........

andy

[BenjiBoy650]

I don't think the brakes are different

Most likely what it is is that V6's don't come with 15's while the I4's do, that's why V6's don't offer a 15" option.

[Accordca]

Well I don't have a V6, mine is an EX-L (leather, sunroof, the works)... Although this may be different from what you know it by since I live in Canada and they sometimes change the model IDs.... but I assume it would be the same as the EX 14 you mentioned....

[Accordca]

I just wanted to let you all know that for those with 16 inch tires on your accord, it's actually RECOMMENDED to go down to 15 inch for winter tires. I spoke with an expert in the tire business and he said that the smaller tires are not only cheaper, but they provide much better traction on snow and ice. So, for all of you in the snow belt, move down to 15 inch rims and get 205/65/15 tires so your rolling diameter stays the same.That won't affect any of the engineering on the car.

He also said to stick with genuine honda rims instead of after market because of the centre hole, and I got original honda rims from a dealer at a pretty good price of $58 (Canadian), which is competitively priced with after market rims up here.

Hope this helps.

[avexnsx]

Originally Posted by Accordca

I just wanted to let you all know that for those with 16 inch tires on your accord, it's actually RECOMMENDED to go down to 15 inch for winter tires. I spoke with an expert in the tire business and he said that the smaller tires are not only cheaper, but they provide much better traction on snow and ice. So, for all of you in the snow belt, move down to 15 inch rims and get 205/65/15 tires so your rolling diameter stays the same.That won't affect any of the engineering on the car.

He also said to stick with genuine honda rims instead of after market because of the centre hole, and I got original honda rims from a dealer at a pretty good price of $58 (Canadian), which is competitively priced with after market rims up here.

Hope this helps.

Which Honda rim did you get?

[Accordca]

I got Honda rims made for the Accord... didn't know there were different ones. model # is 42700-SDA-A91, Wheel Disk 39B.

That is about all I can tell from them.
Sorry

[avexnsx]

Originally Posted by Accordca

I got Honda rims made for the Accord... didn't know there were different ones. model # is 42700-SDA-A91, Wheel Disk 39B.

That is about all I can tell from them.
Sorry

sorry... I meant to ask are they steelies? or Alloys?