2. I'm writing this in the context of my son having an 04 S that he bought and intends to drive through the winter here in Indy, although I have talked him into keeping his Scion tc for the first winter just in case he needs a back up.
3. His 04 has Sumitomo HTR Z III tires on it, if memory serves, an inexpensive summer tire. I had read here where summer tires don't do well in the cold, not just poorly in the snow.

5. Since he has his Scion tc he can drive when there is snow, if he decides to do that instead of putting on the snow tires, can he drive on the summer tires when it gets cold and there is no hint of snow?
6. I know that braking distance is compromised with summer tires in the cold (even A/S are), that is why I told him 40* is where he should put on snows.
7. Just how bad does it get with summer tires on dry payment in freezing weather, what about in the teens, or around 0*, even below 0*?

 

Snow tires or no tires. Those summer tires work well during the summer because they sort of "melt" to the pavement. They become hockey pucks during the winter and he will have zero traction. All season tires would be a bare minimum choice for winter driving with any precipitation. That being said... if he is careful, and there's dry pavement from point a to point b, he should be able to drive the car with the summer tires, but with any form of precipitation he will have much less traction that he needs especially on turning, downshifting, or sudden acceleration needs. Had a friend who put all season tires on her s, and still couldn't make it up a hill in maryland with even the wink of a snowfall.

 

Moved to Wheels and Tires

Ive driven my star specs in snowy weather. There is a noticeable loss in grip, but we made it home. If I lived up north I'd have two sets of wheels. jm2c.

Just go with all seasons...there is no need for "snow" tires on an s2000. If you need snow tires on an S...you need another car for winter

 

It gets very bad. If there's a risk of snow in your area, I suggest not driving or getting snow tires.

I got my S in late March here in Chicago, it came with the stock (and original from the factory) S04's, 2480 miles on them but not dry-rotted or hardened with age so they were in overall good condition. I went out the second morning with the temperature slightly above freezing, and the car was a scary handful. About 2 miles from work, we began to get a mix of sleet/snow, and it was white-knuckle putzing around in 2nd gear the rest of the way.

I would not recommend snow tires in chilly/cold temperatures at all.

 

I live in Indy as well and I am about to enter my fourth winter with the S2000. I have winter tires on my stock rims which I swap out in early December each year. This late swap is made possible by the fact that I can work from home if I absolutely need to, so I don't change to the winter tires until there's a threat of prolonged snowfall on the streets. Basically if I have to work from home for more than 1-2 days in a row due to unclear roads that's when I bite the bullet and finally put the snow tires on.

Driving with summer tires below 40 degrees is obviously not the best choice, but if the roads are clear it will be perfectly fine. Just have to respect the lowered limits due to running the tire well outside of its intended range of use. I would not do this on a regular basis--I recommend a second set of tires if repeated driving in sub-freezing weather is desired.

I disagree with the all-season tire idea. If you're going to the trouble of buying another set of rims and tires, best to go ahead and get snow tires to ensure the car will actually make it through everything without issue.

 

Summer tires are still going to grip better than all seasons when it is dry out, even when it is cold.

 

Make the debate of cold vs snow and it's a different story.
If you're careful, summer tires are fine in the cold. No hot-headed driving and your son will be OK if he's easy on the inputs.
In the snow, however, summer tires are not sufficient and very dangerous - sketchy, quick to lose traction at the slightest input and severely compromised control/braking.
Winter tires are highly recommended in that case.

 

1. I assume you meant to say "summer tires," not, "I would not recommend snow tires in chilly/cold temperatures at all."

 

1. First winter (2010) that I had my S, I had new Michelin A/S tires on my car (didn't need summer tires for white-knuckle driving , and wanted 20k+ treadwear ), and I got caught in less than an inch of snow, and learned my lesson; I immediately put my snows on (Blizzaks) that I had bought on 16 inch rims like new for my 04. ($600, and had to drive 3 hours in my Corolla to get them; then bought another set of Dunlop winter tires on 16 inch rims here in town for $200, couldn't pass it up. , my wife is still hacked that I got 8 tires and rims stacked in the garage, but she hears, "But honey, I will save hundreds of dollars in the future!)

 

1. If he keeps his tc, then he doesn't need to buy another set.
2. I have an extra set of rims and tires I picked up 3 yrs. ago, and I will sell him a set for a Dad price (what I got in them), so it's really just a matter of whether he keeps the tc, which he wants to sell for $10k, but I'm trying to influence him to have a "back-up" car for general reasons, not just snow.