The DriveWerks Newsletter:
Volume 10 - Preparing Your Car for Winter Driving
Hello fellow car lover,
Welcome to the 10th Issue of DriveWerks Car Talk Manual!
Part II of my column on preparing your car for winter driving. Last week we talked about motor oil, batteries, and emergency equipment. This week, I'll discuss snow tires, bad weather driving, and the effects of salt on your car. Finally, in next week's newsletter, I'll talk about how to properly store your classic car for it's long winter hibernation.
Read on, and thanks once again for your support,
Wayne R. Dempsey
Owner of DriveWerks
Your tires are the only thing between your car and the road. The proper maintenance of all of the other systems on your car will be useless if your tires are the weak link. It's important to prepare your tires for winter driving long before the snow hits, so you're not stuck with a dangerous situation.
First of all, there are three main types of weather tires: Snow Tires, All Weather Terrain (all-season), and everything else. All weather terrain tires are an excellent choice for locales where there's a minimal amount of snow and ice throughout the year. In general, these all-season tires (also sometimes called "M+S" for "mud and snow") are a good compromise so that you can maintain one set of tires year-round. Good environments for these would be in Seattle, where it doesn't snow often. I run these tires on my 4x4 Pathfinder here in Los Angeles because I sometimes take it up to the mountains where it is snowy. However, if the temperature drops below about 10-15º F, the rubber compounds in these all-terrain tires begin to deteriorate in performance, and you should switch to dedicated snow tires.
Snow tires are designed for extreme environments, and are often indicated on the side by a small picture of a mountain or a snowflake on the sidewall of the tire
They are specially formulated with tread and rubber composition that will work better in extreme cold temperatures. Tire grip is affected by outside temperature - a decrease in temperature results in a decrease in grip. Snow tires are specially formulated to maintain their grip in very cold climates. On the other hand, they wear a bit more in warmer climates and are not necessarily ideal for driving in the summer months. If you are driving in snow, and you don't have all-terrain or snow tires on your car, then you should definitely use snow chains. Running regular summer tires in snow is a recipe for disaster.
I recommend that everyone who runs snow tires have an extra set of wheel rims that they can mount the snow tires on. That way, it's really easy to switch them back and forth at the start of the season. Avoid mixing and matching tires throughout the seasons - don't place snow tires on the rear and regular summer tires on the front. With today's modern traction and braking systems, cars need good grip from all tires at all times - not just from the two drive wheels. Having four good snow tires will encourage good traction and also limit the amount of skidding and spin-outs that may occur.
Make sure your tires are properly inflated - this can affect traction in snow. Also check the tread wear - worn tires will obviously have reduced traction on snow covered roads. There are typically wear indicators on the tread of the tire. Don't mix different brands and models of snow tires - try to keep them all the same to maintain equal traction on all four wheels.
Starting Your Car
If your car lives in a non-heated garage, then you might want to invest in what is known as a block heater. This device pre-warms the coolant in the car so that it will be easier to start in cold weather. A warm engine will start more easily, will achieve its optimum operating temperature more quickly, and it won't have to work as hard to pump cold oil throughout the engine block. In addition, a block heater drastically reduces noxious emissions that are created by your engine when it's warming up and will help increase your overall fuel mileage. If you have a block heater, make sure that you set it on a timer to start about two hours before you plan to drive the vehicle - there's no need to leave it plugged in all night.
Starting your car in very cold weather can be a semi-religious experience. I can't tell you how many times I've gone to start cars and whispered a tiny prayer right before. The good news is that if your battery and engine are well maintained, your car should start perfectly fine, even in very cold weather. Make sure all of your accessories (lights, radio, etc.) are turned off before you start the car - your battery will need all of its juice to turn the car over. If the car doesn't start, don't turn it over for more than 10-20 seconds or so. Doing so can harm the starter, and also deplete your battery unnecessarily.
Once you get the car started, don't rev the engine. The oil in the engine will be very cold, and oil pressures will be very high. When you rev your engine, the oil pressure will increase, possibly damaging some seals in the engine. Let the car warm up for about a minute, and then you can start driving it slowly. I don't recommend letting the car idle in place for any long length of time - it's best to just start driving slowly. Don't let the RPMs of the engine go too high when the engine is still cold - you don't want to increase the oil pressure too high inside your engine. Keep an eye on the oil pressure gauge or lamp on your dash board. If a seal does happen to fail, you will most likely lose some oil, and your oil pressure will decrease. Turn off the engine immediately if this happens, as you can save yourself an expensive engine repair later on. In general, the rule of thumb is to ease the car into the drive without fully getting on the throttle until it's completely warmed up.
Driving in the Snow
It amazes me how many people don't realize how dangerous it is to drive in the snow. Although I live in Los Angeles right now, I do try to escape to the mountains to go skiing at least once a year. In Los Angeles, it only rains about 3 times a year, and it never snows. So, up in the mountains, you often encounter a whole bunch of people who have hardly ever driven in rain, let alone snow. The results can be disastrous.
First off, there's the 4x4 over-confidence problem. Many people over the past few years have bought SUVs or 4x4 pickup trucks. It's not difficult to understand that these owners would want to use their 4x4s in the snow. However, most cars and trucks with all-wheel-drive give a false sense of security to their owners. The trucks are very capable at finding traction in the snow, however, some owners don't realize that they are subject to limitations on braking. 4-wheel drive does not help with braking in snowy and icy conditions. Since the trucks grip the road much better, owners have a tendency to drive them much faster than they should be driven under the conditions. When it comes time to brake under emergency circumstances, then the reality of decreased traction becomes very apparent. In this situation, it is where a system like Anti-Lock Brakes (ABS) takes over, and the 4x4 vehicles have no significant braking advantage over a two wheel drive system. Basically, ABS is to stopping, what 4x4 is to going.
Anti-Lock Brakes (ABS) is one of my favorite inventions. The beauty of ABS is not that it will allow you to stop quicker on slippery surfaces (although it certainly does), but that it allows you to maintain control of the steering of the car while the car is sliding. On cars without ABS, the wheels have a tendency to lock up when the brakes are suddenly applied while driving on a slippery surface. ABS takes over the braking from the driver and quickly pulses the brakes so that they never quite fully lock up on the surface. This allows the driver to continue steering the car while applying the brakes quickly. Cars without ABS tend to skid and slide (especially in the snow), and at that point, you're basically going in the direction of the skid - there's typically not much you can do to stop it. Before the winter season starts, verify that there are no ABS warning lamps lit on your dash, and that the system is working well.
If you haven't driven in snow before, I suggest that you practice prior to getting on the roads. Find an empty (very empty) and wide open (very wide open) parking lot when it snows and go practice. Get a feel for the car as it turns and slips. Get a feel for when the Anti-Lock Braking (ABS) system takes over. Getting familiar with the car in a controlled environment like this is vital to maintaining a cool composure on the road. Check the brakes and see how much stopping distance you need. Determine how your car moves in a skid. It's important to remember that front wheel drive cars behave differently than rear wheel drive cars, and different makes and models of cars will have varying performance characteristics as well.
Driving with snow chains is a good idea in very snowy and icy conditions. A lot of people don't use them all the time though, because they can be a pain to install and remove (particularly in cold weather). There are several different types of snow chains, but for the most part they are all very similar. The one key point to remember is to not drive faster than 30 miles-per-hour with the chains installed. Any faster, and the chains may come loose and begin to fly around. I was talking to one tow-truck driver this past season who commented that he'd seen more than one instance where people drove too fast with the snow chains on, and they broke free and severed one of the rear brake lines. Needless to say, this would not be a good thing to have happen.
Although DriveWerks has no financial relationship with AAA, I wholly recommend their roadside service benefits, particularly if you have an older car that just may not be 100% reliable. The network of AAA tow truck drivers will come to rescue you guys in the middle of a snowstorm (been stranded there) and also in the middle of the Mojave desert (unfortunately, been in trouble there too). If you run out of gas, they'll bring some. Lock yourself out of your car, and they'll bring over a locksmith. They'll test your battery for you and help you replace it if needed. Up to four free Roadside Assistance calls per year are included as part of your membership, along with a host of other benefits. AAA is one of those unique non-profit services where there really isn't a catch - it's just simply a very good idea. (more info: www.aaa.com). Sometimes your insurance company will offer roadside assistance as well (like Hagerty's Classic Car Insurance - www.hagerty.com). Although I haven't used their particular service quite yet (my fingers are crossed), old classic cars and roadside service seem to go hand-in-hand.
Salt & Steel
Just about every snowy locale uses salt on the roads to help melt the snow and ice, and keep the roads safer. I've always wondered exactly how this worked, so I did some research. As salt is spread on the roadway, it forms a mixture when the two begin to melt. Typically, the salt is spread on the roadway prior to the first snow. In short, the combination of salt and water together lower the freezing point of the mixture. As the snow and ice melt on the roadway, the ice layers on the top surface of the roadway separate, forming slush that can be easily plowed to the sides of the road. As the salt and water melt together, the presence of salt within the water effectively contaminates the purity of the water and thus lowers its freezing point.
Current temperatures, weather conditions, and the time of application all affect the ability of salt spreading to deice the road. At 30º F, the salt is about five times more effective at decing than at 20º. A 10% salt solution freezes at 20º F and a 20% salt solution freezes at 2º F. If you sprinkle salt directly onto ice, you will see the melting process begin. Once the salt is combined with the liquid water, it lowers the freezing temperature, and will not resolidify. However, if the temperature is lower than about 15º F or so, the salt will have almost no effect - the ice needs to be within a semi-close temperature range of it's normal melting point - the solid salt crystals cannot get into the structure of the solid water to start the dissolving process.
In reality, any foreign substance dissolved in water will perform the same as the salt. Sugar or even alcohol will also perform the same melting process and reduce the freezing temperature of the mixture. Salt is used on roads because it is very abundant, cheap, and readily available.
What are the downsides to using salt? Runoff from the roads turns the snow / ice mixture into a salty mix. Road salt application needs to be carefully controlled as to not affect local water supplies and creeks/streams. In addition, the salt speeds up rust formation on your car. When the salt is dissolved in water on a metal surface, the conductivity of the water is increased (iron atoms are conveyed more easily and quicker towards cathodes in the metal), thus accelerating the corrosion process. In addition, chloride ions present within the salt / water mixture accelerate the dissolving of iron.
I recommend that you wash the underside of your car often if you are often driving on salty roads. Modern cars have rust-proof galvanized coatings on their bodies, but these could be best described not as rust-proofing, but as rust-reducing techniques. The galvanized metal will slow down the rust, but only to a point - as the galvanized coating is eaten away, the steel underneath will begin to rust. Alas, there's way too much information to convey on the seemingly simple topic of rust prevention - perhaps I'll cover it in a future column.
Well, there you have it. Follow these guidelines, and you should be well protected against mother nature this season!
Well, that's all for this week, stay tuned for the next topic!
Thanks again for your support!
Wayne R. Dempsey
Principal Owner of DriveWerks
Got questions? You can email me at email@example.com or ask a question in our How-To Forums.
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