summer tire in the snow
 

last year I was forced to drive through 2 snow storms on my way back from the BJ auction in Scottsdale . my new to me 96 CE LT4 had Nitto NT 555's mounted, I don't think I even knew summer tires were on the car at the time. I had to roll. my question : next week I will mount 2 new Nitto's and leave the 7 k miles "snow tires" on the rear. is this likely to cause any issues ? I see on Nitto website that use of summer tires below 45(I was way below) will void warranty. How would they know that happened ? Tires seem fine to me, but what do I know living by the grace of GOD in the Deep South.

The tires become hard in low temperatures and thus have substantially lower grip for handling and braking. I really doubt thou that your tires were damaged by driving in the cold. Do you see any obvious signs of belt shifting or anything else out of the ordinary?

no issues so far after 4k miles. thank you for reply

It will absolutely be a problem using the summer tires in the snow, if you want your tires to last.. Here's the deal....

The rubber compound is not designed for the cold, so it will crack. Not only driving on them, but storing them in the freezing is enough to damage them.
Its not really a traction issue though. Its more about protecting your rubber. If you don't care for them proper, the next season it could be like driving on dry rotted tires,. And then on next years autocross when you really need them, they wont deliver. Technically, the rubber hardens in cold, and wont deliver the same good traction they were rated for. So if driving on clear pavement in the cold, it could be a safety issue, because they wont grip well. But probably fine if driving mildly. But in actual snow, they might handle rather well, because snow driving isn't really about stickiness of rubber. As long as you have good tread you'll likely grip down on the snow adequately. The Nitto 555s have all sorts of good tread blocks and grooves to bite the snow. My stock 1985 Goodyear eagles (optimized for summer tire) handled snow storms of Maryland over the years just fine. At the end of the day you got to ask, " why did you buy Nitto Ultra performance tires that don't have a long treadlife for a street car?" Because you want the fast driving performance! So why not protect the tires for that purpose? Why wear them out in Winter months, where they wont perform idealy, and where it might compromise their reliability and performance in the later summer months, that you bought them for ?
In my opinion there are two good options..... 1) buy an all season performance tire, if you live in a region that gets cold, or 2) buy a second cheap set of rims with winter or all season tires, to get you through the winter months. You'll get twice the life, with twice the tires. there isn't a down side, other than storage space.

I cant comment on how long the Nitto 555 will last when abused with Cold winter use. That would have to be answered by Nitto or by someone that has decided to abuse his tires with lengthly winter use. Someone said on a different thread that Nitto 555 might be safe to use as low as 15 deg without damaging them, just with less tractions, so concluded after speaking with Nitto. But that is different than anything Ive read from Nitto, Suggesting they were superior to Continental Summer tires that couldn't be driven in winter.

I just bought 555s for my car. But I don't plan to keep them on in the winter to find out.

no visible cracks, but will keep close watch. thanks for detailed response

Way back when dinosaurs roamed the earth and no one had ever heard of ultra high performance summer tires I put a set of the latest and greatest Michelin tires on my '84 RX7 GSL-SE and headed up to my folks in PA for Christmas and NH to ski for New Years. Previous tires were Pirelli P6's which had made the same trip twice with no problems. Long story short, got into some light snow on the WV turnpike, could not make it up modest grades, had to stop and put on cable chains. C4 Vettes on GY Gatorbacks were cruising right past me. Caught up to a snowplow spreading salt, took the chains off and followed him to Charles Town where I proceeded to spin a 360 in the middle of 3 lanes of traffic on a bridge. Finally got to my parents who had a long drive that went down, across a bridge and up to the barn. Abandoned the RX-7 at the lowest point in the driveway until morning, put the chains back on it and drove to the local Goodyear store and bought a set of their best radial snow tires called F32. They bagged up the Michelin's and threw them in the back. I threw them in the hay loft and forgot about them until spring. Meanwhile the RX7 is like a mountain goat on these F32's. It could go anywhere, stop on a sheet of ice and pull right out. No problems getting around NH ski areas.

Next spring my dad shipped the Michelin's down to me and I took one look at them and saw the bead rubber was broken on every one of them. Big chunks broken right out, the tires were trash. I tried to get Michelin to replace them, no dice. Michelin's NA headquarters is right across the street from my work, I talked to a couple of their engineers. They said, that's a safety feature on those tires, they have so little traction in the snow you can't even get out of your garage. I said it's not so funny when you are on a road trip. Never got a bit of satisfaction out of Michelin, would not stand behind their product a bit. Out of desperation, I talked to the local Goodyear store, they said since I had the work done in one of their stores they would give me a store credit for the full amount I had paid for the Michelin's! I bought a +1 set of Panasport wheels and 4 GY Gatorback tires and kept the F32's on the stock rims. I've had summer and winter sets of wheels and tires on every vehicle since. These days, the ultra high performance tires are even more highly biased toward high temps and many tell you to not even move them below 40 degrees.