265/65/17 or 265/70/17, which is better?

[scott78945]

I was having a conversation with someone today on which would be a better tire. I looked up on the Toyota site and it states that the SR5 4Runner gets 265/70/16 wheels and I have the SE which gets the 265/65/17. Which tire will give better traction in snow? I am being told that the thinner the tire the better traction but that doesn't seem right. I would also assume that the 16" wheel on the SR5 has something to do with it also...can anyone shed some light on this?

 

[sharp4runr]

Both those tires are 265mm wide (first number). The second number 65 or 70 is a percentage of the first number that is why the lower the nuber the lower the sidewall.

Yes the thinner the tire the better the snow traction. The reason being is that a thinner tire will "plow" through the snow better than a wider tire. The wider tire will tend to ride on top of the snow instead of pushing through it.

You could have found all this out at Tirerack.com FAQ section :

 

[cpayne5]

I was having a conversation with someone today on which would be a better tire. I looked up on the Toyota site and it states that the SR5 4Runner gets 265/70/16 wheels and I have the SE which gets the 265/65/17. Which tire will give better traction in snow? I am being told that the thinner the tire the better traction but that doesn't seem right. I would also assume that the 16" wheel on the SR5 has something to do with it also...can anyone shed some light on this?

The difference in width between the 265/65r17 and 265/70r16 is only 0.2" with the Dunlop AT20s.

Here's a nice writeup on the topic that gives the "skinnier is better" view: http://www.expeditionswest.com/research/white_papers/tire_selection_rev1.html

 

[cpayne5]

...
Yes the thinner the tire the better the snow traction.
...

Depends how deep the snow is. :

 

[sharp4runr]

Depends how deep the snow is. :

explain please as I guess I'm not as enlightened as you

 

[cpayne5]

explain please as I guess I'm not as enlightened as you

Skinnier tires dig down, like you said, but if you don't have anything to dig down to, then you're stuck. If you've got (very) fat tires, then you (can try to ) float over the top.

 

[sharp4runr]

I've always thought the thinner would work better because the rally cars use them when driving in the snow. Granted those tires are also studded but you'd think if the wider tire performed better they'd use wide studded tires. Instead the use the skinny tires that are studded.

 

[cpayne5]

Skinnier tires dig down, like you said, but if you don't have anything to dig down to, then you're stuck. If you've got (very) fat tires, then you (can try to ) float over the top.

Kinda like this:

http://www.toyota-4runner.org/photopost/showphoto.php?photo=331&password=&sort=1&cat=998&page=1

 

[Bluto]

I've always thought the thinner would work better because the rally cars use them when driving in the snow. Granted those tires are also studded but you'd think if the wider tire performed better they'd use wide studded tires. Instead the use the skinny tires that are studded.

Think hiking boot vs. snow shoe. A hiking boot won't do much good in 3' of snow. Most owners will never encounter very deep snow where wider is better.

 

[sharp4runr]

Kinda like this:

http://www.toyota-4runner.org/photopost/showphoto.php?photo=331&password=&sort=1&cat=998&page=1

ahhh ok, now I understand

 

[Falls]

Re: Re: 265/65/17 or 265/70/17, which is better?

The difference in width between the 265/65r17 and 265/70r16 is only 0.2" with the Dunlop AT20s.


Only .02" between a 65 and a 70 series tire ???

I'm switching fron the stock 265/65/17 to a Revo 265/70/17 and thought people were saying it was about an inch taller tire. Everyone was saying how it filled up the wheel well's better. I don't think you would even notice .02"

 

[cpayne5]

Re: Re: Re: 265/65/17 or 265/70/17, which is better?

The difference in width between the 265/65r17 and 265/70r16 is only 0.2" with the Dunlop AT20s.


Only .02" between a 65 and a 70 series tire ???

I'm switching fron the stock 265/65/17 to a Revo 265/70/17 and thought people were saying it was about an inch taller tire. Everyone was saying how it filled up the wheel well's better. I don't think you would even notice .02"

Width not height. 0.2" not .02"

Your Revos will be 1.1" taller than the stockers. (31.7" vs 30.6")

 

[jlboers]

Re: Re: Re: 265/65/17 or 265/70/17, which is better?

The difference in width between the 265/65r17 and 265/70r16 is only 0.2" with the Dunlop AT20s.


Only .02" between a 65 and a 70 series tire ???

I'm switching fron the stock 265/65/17 to a Revo 265/70/17 and thought people were saying it was about an inch taller tire. Everyone was saying how it filled up the wheel well's better. I don't think you would even notice .02"

Correct. the revo's are about 1" taller. the 70's are 5% taller than the 65's so you gain 26.5mm in diameter which is about an inch. 5% of 265 x 2

 

[scott78945]

Well thanks all for the replies.

 

[OUTRNNR]

Traction in snow will be roughly the same for an identical tire width but different aspect ratio. Like was stated earlier, the 265/65 is only .2 inches wider than the 265/70, thus giving a negligible advantage in traction to either tire.

However, narrower tires will offer better traction overall in the snow. This is because the skinnier tire has a smaller contact patch to the road, increasing the force per square inch of contact with the ground. As some of you may know, friction, the phenomenon that makes driving (as well as many other things!!) possible, will increase with this larger force given a constant coefficient of static friction:

F=u*N (Physics is Fun!! :arrow: )

Where F is the force of static friction holding the tires to the road, u (or mu) is a coefficient of static friction which depends on the road conditions (ratio between 0 & 1, where 0 is frictionless and 1 is maximum friction), and N is the normal force that the road puts on the car which, as proven by Newton's third law, also happens to be the same force that the car puts to the road (which I explained above).

Its easy to see from the equation that for any constant mu, the force of friction will INCREASE with the force (N) put to the ground by the car and the tires, so any increase in this force which comes from the increased pressure of a smaller contact patch will be beneficial to traction on snowy roads.

Hope everyone was able to follow that

 

[Falls]

Re: Re: Re: Re: 265/65/17 or 265/70/17, which is better?

Width not height. 0.2" not .02"

Your Revos will be 1.1" taller than the stockers. (31.7" vs 30.6")

Whooooops, A little brain fade there.....

 

[sharp4runr]

Re: Re: 265/65/17 or 265/70/17, which is better?

The difference in width between the 265/65r17 and 265/70r16 is only 0.2" with the Dunlop AT20s.

Here's a nice writeup on the topic that gives the "skinnier is better" view: http://www.expeditionswest.com/research/white_papers/tire_selection_rev1.html

How is the width different on these two tires if both list the section width as 265?

Unless the different tire manufactures are creating the tire differently thus making the width slightly difference. I don't think this was the case as the brand and type of the tire was never brought up.

 

[mjbuzby]

70's

will they fit in the spare tire location?

 

[scott78945]

What is the thinnest tire that can be put on a Runner safely? I am most likely going to be getting new tires this fall for next winter and was going to get the 265/70/17 Revos but everyone is telling me to get smaller tires. I figured the 265's were the norm and I shouldn't stray from them.

 

[OUTRNNR]

What is the thinnest tire that can be put on a Runner safely? I am most likely going to be getting new tires this fall for next winter and was going to get the 265/70/17 Revos but everyone is telling me to get smaller tires. I figured the 265's were the norm and I shouldn't stray from them.

Although the stock tires (265 width) are fairly wide for an SUV, that doesn't mean that you shouldn't get that size. If you are driving in snow a set of 265 width REVO's will be more than adequate based on the reviews they've gotten on this forum. Getting narrower than stock tires will only degrade your dry weather performance and handling.