Weather turns and tires
No matter where you live this could be the El Nino winter for the history books. North south east and west the weather people are calling for more snow, more rain and colder temperatures. Of course not all conditions for everyone but probably something not nice and possibly dangerous for just about every part of the country. So now would be the time to prepare for what lies ahead. Even though it may not materialize for some or all of us in my world it is far better to be prepared and not need it than not be prepared and need it.
So let’s start with one of the most important parts of cars when the weather turns; tires! What you need for tires will depend on the type of weather you get where you live. If you get snow or even a lot of days where the temperature is at freezing or below you probably need winter tires. Yes the temperature is as important as snow and ice because temperature causes huge changes in the way tires grip the pavement. So if you call winter tires “snow tires”, don’t. They aren’t snow tires, they are winter tires and they are designed to do a lot more than help you get moving in snow. The other thing with winter tires is they may be highly beneficial even where there is zero snowfall. The rubber in tires is a complex concoction of rubber and other chemicals blended to make the tire grip, wear well, shed water, ride smooth, etc. But no one tire can do everything the best so most tires are designed to do all things in a middling manner. Not great at anything and usually not terrible at anything except cold weather traction.
Due to the chemistry needed to make the tires wear a long time the rubber becomes stiff and brittle when the temperature drops. This change in rubber flexibility and grip means that as the temperature drops your
stopping distances become longer or in some cases significantly longer. So much longer that if it were not for the car blocking your path you would stop 20 or 30 feet past its front bumper. Of course that doesn’t
happen because you hit the car and let me tell you that does shorten your stopping distance and screws your relationship with your insurance carrier.
The other thing that happens is that you lose the ability to steer. No matter how well your car handles in normal conditions when the thermometer drops so does your ability to go round corners. Did you ever
wonder why so many more cars slide off exit ramps on cold days then on hot days? It’s because the car couldn’t get enough traction to maintain control around the corner. After all once you reach the maximum grip of
your tires nothing else matters. This is why race cars do that crazy back and forth weaving when they’re on a caution. They don’t want their tires to get too cold because when that happens traction goes away. The
same is true of your daily driver.
Winter tires have a vastly different rubber compound and tread design to compensate for the shortcomings of all-season tires. So if it gets cold for any appreciable time where you live you might want to consider
winter tires. Oh make that four winter tires because you don’t want one end of your car to have a lot of traction and the other end to have a lot less. That’s a good recipe for a skid.
Another thing to consider is that most drivers who buy winter tires buy them because they want to be able to get going faster in snow. But does that really make sense? I think not because going faster in bad weather
never makes sense. The truth is that winter tires are to help brake better, steer better and maintain control. Being able to spin less to get going is simply a side benefit.
Same is true for four-wheel and all-wheel drive owners. Although they can make you get going they still only have four wheel brakes just like vehicles with two-wheel drive. So going like crazy in your 4X4 is just
plain stupid because sooner or later you will have to stop. Trying to stop a 2 ton beast in low traction conditions can be a chore because the very instant you lose traction on all four wheels you have no ABS or traction control, and no ASR plus you have instantly converted your 4X4 (four-wheel drive) into a 4X0 (no wheel drive).
But what about those of you who live where it doesn’t snow, you don’t get ice and it doesn’t stay cold for days on end? Well you could have your own set of issues to contend with. Many areas of the country will see abnormal amounts of rain and rain can be as dangerous as ice. Here again traction is the issue. As tires wear down their ability to resist hydroplaning decreases exponentially.
If you don’t know what hydroplaning is you don’t want to find out by experiencing it. When a car hydroplanes the tread of its tires fill up with water. With the tread full of water the tire lifts off the pavement and rides on the water between the tire and the road. This is very much like what happens when you water ski. But when you water ski you can tilt your skis to get resistance so you can turn. On a car you can’t tilt the wheels so you are just sliding on water with zero control, you can’t steer or stop until the car settles back down to the road and
regains traction. Better hope you don’t find anything in your way until you do regain traction because there is zero you can do to prevent hitting it.
The more worn the tires the more shallow the grooves and the easier it is for them to fill with water. But this problem is not linear. In other words if 10% tread wear causes a loss of 10% of your hydroplaning resistance 20% doesn’t necessarily mean 20% loss of resistance. Actually 20% tread wear may equate to 30% loss in resistance to hydroplaning 30% tread wear may equal 35% resistance loss and so on.
So the old suggestion that tires are good until they wear down to 2/32” is no longer wise. Because of the changes in the way modern tires work it is now considered prudent to look toward replacement at 4/32” to be
safer in wet conditions.
No matter where you live or what you drive there is only one way to be safe and that’s by having good tires. Because tires are the vehicle’s only physical connection to the road surface they are what determines
how well the car stops, steers and accelerates. Once the tires lose their grip on the highway you’re in trouble so concentrate on tires as your first safety concern on your car.
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