The first cold morning of the season has a way of finding the weak spots in a car. A tire pressure light that stayed off all summer comes on. The engine turns over a little slower than it did in September. Neither one means something is broken, but both are worth a look before the weather gets serious.
The good news is that the two parts most affected by cold, the tires and the battery, are also the easiest to check in your own driveway. Set aside half an hour on a weekend and you can head into winter knowing where you stand.
Check tire pressure when the tires are cold
Air pressure in a tire falls as the outside temperature falls, which is why warning lights tend to show up on the first chilly mornings. A tire that was right on target in August can be noticeably low by late October without having a leak.
Check the pressure before you drive, or after the car has been parked for at least three hours. Use the number on the label inside the driver’s door frame or in the owner’s manual. The figure molded into the tire sidewall is the most the tire can hold, not what your car is meant to run on.
Check all four tires, and the spare if your car has one. If one tire is much lower than the others, or keeps losing air after you top it off, have a shop look for a puncture or a leaking valve.
Look at how much tread is left
Tread is what moves water, slush and snow out from under the tire. As it wears down, stopping distances on wet and snowy roads get longer, well before the tire looks bald.
The legal and safety minimum is 2/32 of an inch. The penny test is a quick way to check it. Put a penny into a tread groove with Lincoln’s head pointing down. If you can see the top of his head, the tire is at or below that minimum and due for replacement. Many drivers in snowy areas choose to replace tires earlier than that, because grip in snow drops off as tread gets shallow.
While you are down there, look for uneven wear across the tire, cracks in the sidewall and anything stuck in the tread. Uneven wear is often a sign that an alignment or rotation is overdue.
Decide whether all-season tires are enough
All-season tires are built to do a reasonable job in most conditions, and for drivers who see mild winters they are usually fine. The rubber gets stiffer as temperatures drop, though, and stiff rubber grips less. Winter tires use a compound that stays flexible in the cold, along with tread designed to bite into snow.
A common rule of thumb from tire makers is to think about winter tires once daily temperatures settle at around 45 degrees Fahrenheit or lower for the season. If you regularly drive on snow or ice, or through mountain passes, they are worth serious thought. If your winter is mostly cold rain with a rare frosty morning, a good all-season tire with plenty of tread may be all you need.
The sidewall can help you tell tires apart. The M+S marking is based on tread pattern. The three-peak mountain snowflake symbol means the tire has passed a snow traction test. For a fuller walk through the choice, including fitting four matching tires and storing the other set, see this guide to how winter tires compare with all-season tires.
Give the battery a quick check
Cold weather is hard on a battery from both directions. A cold engine needs more power to start, and a cold battery has less power to give. A battery that coped in summer can leave you stranded on the first truly cold morning.
There are a few things you can check yourself:
- Find the date sticker or stamped code on the battery. Many batteries last three to five years, so one near the end of that range deserves a test.
- Look at the terminals. White or green buildup can get in the way of a good connection.
- Make sure the battery is held firmly in its tray and the cable clamps do not move by hand.
- Pay attention to how the engine starts. Slow cranking or dimming lights at startup are early warnings.
If any of those raise a doubt, ask a shop or parts store to test the battery and charging system. The test takes a few minutes and tells you far more than a visual check can. Electric and hybrid owners should also expect less driving range in the cold and plan charging stops with that in mind.
Finish with the small things
A few other items take minutes and make winter driving easier. Replace wiper blades that streak or chatter. Fill the washer reservoir with fluid rated for freezing temperatures. Check that every exterior light works, since winter means more driving in the dark.
It also helps to keep a small kit in the trunk with an ice scraper, a flashlight, jumper cables, a blanket and a phone charger. The National Highway Traffic Safety Administration lists more ideas in its winter driving tips.
Know when to hand it to a shop
Checking pressure, tread and battery condition is well within reach for most owners. Mounting and balancing tires, diagnosing a charging problem and tracking down a slow leak are jobs for a technician with the right equipment.
If a check turns up something you are not sure about, write down what you saw and when, and take that to the shop. For plain explanations of warning lights and common car problems between visits, TunedDrive covers them in everyday language.
Half an hour now is a lot easier than a dead battery or a slide through an intersection in January. Check the tires, check the battery, and you will start the season with far fewer surprises.
