Aspect ratio and winter traction

I'm running 265/70/17 in all kind of conditions without any problem. The most important thing for those contitions is to run quality dedicated snow tires.

My 2 cents if you believe that living in a city receiving between 10 to 13 feet of snow every year count for some experience.

 

I have run 245's, 265's and 285's in a proper winter dedicated tire. They have all worked well for me whether it be packed snow and ice or fresh snow on concrete. As the previous poster mentioned, the rubber compound and appropriate driving technique are real difference makers.

 

"Those guys" are correct in saying 245 is better than 265 in snow and ice, because they are skinnier. It's not a strong opinion either... it's physics. Pressure = Force/Area. The weight (force) of your truck on 245's (less contact area on road) will result in more pressure against the road than 265's.

Your aspect ratio determines the sidewall height of the tire. Taller would obviously allow you to drive through deeper snow, but that's not what the issue is about. We're talking about cutting through a small amount of snow/slush/ice and gripping the road.

 

Oh shit! Brought maths to the table.

Bravo!

 

4 years of engineering school finally paid off.

 

I know all about the maths involved but I never even thought of it!

 

And.. that 4 years of school was totally worth it for that one post.

 

When there's more than 2" of snow, neither size tire is gonna cut through to grip the road. Both will leave a packed tire track. And after 100 cars drive on that road, it's gonna be packed hard to 1/2". Will the 245 still be better than the 265? I get what you're saying about a skinny tire cutting through. A bike tire would cut through 2". But with a 245/265, both are going to pack it.

Or is it that the 245 is still better than the 265 due to "physics" even on packed snow/ice? You can't tell me a 3" wide tire would be better than a 10" tire.

 

Just put 365's on your truck and be done with it.

 

And for the record, its legitimate physics. No need to put it in quotation marks.

Lets say you have a 100 pound weight sitting on a 1 square inch platform. You have 100 PSI (pounds per square inch) acting on the platform. If you take that same 100 pounds and place it on a 2 square inch platform, you then have 50 pounds per square inch.

But at the end of the day.. 10mm, 1 cm or .39 of an inch will NOT make the biggest difference in the world when it comes to traction.

 

It's hard to say whether you'd notice a difference in traction. But yes in theory even if the road is packed hard, a skinnier tire will still have an advantage.

A wider tire would have the advantage in fresh, deeper snow, where you would want your weight to be spread out and float as much as possible.

 

If you put those same weights and platforms on a hockey rink, and pushed them both with equal force, which one is going to stop first?

I'm not arguing- I appreciate the responses! Just wondering if anyone really knows the answer as opposed to a theory. I'm in agreement with the physics (and the theory). Just seems to me that if I need to get my truck stopped real quickly on packed snow, the wider tire would be more helpful in getting me stopped. Particularly if the tires locked up.

 

A train locomotive with smooth steel drive wheels, on smooth wet steel tracks, would work better if the rails and drivers were 10" wide? Better let the Union Pacific and Burlington Northern railroads know they are doing it all wrong.

 

Yeah, The train example was mentioned in an article i read yesterday. The same article encouraged the use of wider over narrower tires on 4x4's on packed snow (and proceeded to use the snowmobile as an example). Would you rather have a winter rated 265 or a slick 225 on snow pack? What works for a train works for a train. My point is there are a lot of variables at play.

 

How can you compare a snow rated tire to a slick? That's comparing apples and oranges.

 

What about abs?! Abs on these trucks actually increase speed.

 

I wasn't comparing them. Just pointing out that there are other variables at play in addition to width.

 

ABS is a wrench in this chain!

 

Common folly of comparing rigid object friction (simple high school physics with constant mu) vs an automotive tire that generates friction through two different mechanisms in non-linear fashion.

 

I'll just leave this here:

https://www.youtube.com/watch?v=wJsLVtkmz0c

Nope, no skinny tires anywhere in this video.