I bought a car with 245/45ZR 17 Tires. It is currently 32 degrees outside. I have always been told that?

Question

the coldest that you should drive a z rated tire is 40 degrees. and even then with great caution. Now I am hearing that because there actually 245/45 ZR17 95W BSW

tires that the Z rating should not be affected by the cold and go ahead and drive if the roads are just cold and dry.. the 95W rating means that they will be safe. True?

Answer 1

The problem is you been told that there's a relationship between two things, when there really is not relationship. It's more of a... coincidence.

A tire's speed rating means what it's certified to sustain. It never says anything about it being cold or not. Obviously this assumes that the tire is at a "normal" temperature. For the tire itself, it's somewhere between 135 and 185 degrees F. After all, that's why Formula cars have "tire warmers". Heck, if you're serious motorcycle racer you can get tire warmers for motorbikes too.

In cold weather, no matter where you live, you really want wet or winter/snow tires, but snow tires are for low speed runs. Clearly you don't run snow tires at 150 MPH or whatever. (in fact, most winter tires are rated Q, max 99 MPH)

So some people started making the corelation that speed and temperature don't mix. As no matter what you do in really cold weather, you'll NEVER get the tires warm enough to optimum operating temperature.

In a sense, that is true. However, with modern tires, at least SOME of that is false. Modern tire compounds gets you better traction in most temperatures than before. So you have to make LESS of a sacrifice in handling than before.

So, let's put it this way: if you want good traction in cold weather / snow, get a set of non-stud winter tires. Swap them for your high-speed all-seasons when the snow goes away.

Answer 2

the Z is only a speed rating for the tire

Answer 3

They will be good after a little warming up 10-15 minutes worth of driving should do the trick.  Trust me no quick moves before that because the tires will have minimal traction.  My history leaving work, speeding through a 15mph S-turn ultimately ripping all the wheels off after pushing through the curve, 1991 GMC Syclone= $5500 dollar repair. I have done this same act multiple other times without incident and associate the cool night as the only variable of change.

Answer 4

I would call my dealer to be sure but these newer cars are all equiped for the weather my mechanic says I don't have to wrm my new truck up for 10 minutes like I did my 96 toyota he said I can start it up and go but I still let it warm up for 5 minutes or so in this weather 33degrees

Answer 5

TRUE!!

Your tires are probably designed for much lower temperatures, AND higher speeds than normally driven.

If you are really worried, have your tires filled with NITROGEN gas.  This gas doesn't change its pressure with "Earthly" temperatures.  Many garages and tire places offer this for a few dollars more.

source: http://www.tirerack.com/tires/tiretech/t...

While a Z-speed rating still often appears in the tire size designation of these tires, such as 225/50ZR16 91W, the Z in the size signifies a maximum speed capability in excess of 149 mph, 240 km/h; the W in the service description indicates the tire's 168 mph, 270 km/h maximum speed.

225/50ZR16 in excess of 149 mph, 240 km/h

205/45ZR17 88W 168 mph, 270 km/h

285/35ZR19 99Y 186 mph, 300 km/h

Answer 6

well of course

32 celcius is rather warm tho.