Several popular winter car maintenance tips are outdated or wrong. Modern cars don’t need a long warm-up, letting air out of your tires doesn’t help in snow, and all-wheel drive doesn’t help you stop. What does help in a Maryland winter: correct tire pressure, good tread, a tested battery, the right coolant, and rinsing road salt off the underside of the car.
Quick answer
- Most modern cars need about 30 seconds to a minute of idling, then gentle driving. Idling for 10 minutes mostly wastes fuel.
- Tire pressure drops as it gets colder. Check it on cold mornings and fill to the number on the driver’s door sticker.
- All-season tires handle light snow, but they lose grip in real cold and slush, especially when worn.
- Road salt and brine speed up rust. Rinsing the underside during winter is worth it.
- Never use plain water instead of coolant, and never pour hot water on a frozen windshield.
Do you need to warm up your car before driving in winter?
Myth: You should let the engine idle for 10 or 15 minutes on a cold morning before you drive.
Fact: That advice comes from the days of carburetors. Most modern fuel-injected engines only need about 30 seconds to a minute of idling before you can drive off. The engine actually warms up faster when you drive gently for the first several minutes than when it sits idling. Long idling burns fuel and doesn’t do the engine any favors. Your owner’s manual may give specific guidance for your car.
There is one good reason to wait longer: visibility. Clear all the snow and ice off the windshield, windows, mirrors, lights and roof, and give the defroster time to clear the glass. Driving with a small peephole scraped in the windshield is dangerous. And never warm up a car inside a closed or attached garage, because carbon monoxide builds up fast.
Does cold weather really lower tire pressure?
Myth: Letting some air out of your tires gives you better traction in snow.
Fact: Underinflated tires hurt handling and braking, wear out faster and can overheat. On regular passenger cars, keep tires at the pressure listed on the sticker inside the driver’s door jamb, not the maximum number printed on the tire.
Cold air takes up less space, so tire pressure drops as temperatures fall. A common rule of thumb is about 1 PSI for every 10 degrees Fahrenheit. That’s why the tire pressure warning light often pops on during the first cold snap of the season. Check pressure in the morning before you drive, when the tires are cold, and add air as needed.
If the light stays on after the tires are filled correctly, or it flashes when you start the car and then stays lit, there may be a problem with a sensor or the system itself. That’s something our TPMS tire pressure sensor service can check.
Are all-season tires good enough for a Maryland winter?
Myth: “All-season” means the tire is built for every winter condition.
Fact: All-season tires are a compromise. They handle wet roads and light snow reasonably well, but the rubber gets stiffer as temperatures drop, and they don’t grip ice or deep slush the way winter tires do. Winter tires use softer rubber and deeper tread patterns that stay grippy in the cold, and around 45 degrees Fahrenheit is the point often cited where they start to have an advantage.
For a lot of drivers around Rockville and Montgomery County, where snow comes and goes, a good set of all-season tires with healthy tread works for most winter days. If you have to drive in every storm, commute early before roads are treated, or head to western Maryland in winter, winter tires or all-weather tires marked with the mountain and snowflake symbol are worth considering. Either way, tread depth matters most. Put a quarter upside down in the tread. If you can see the top of Washington’s head, the tires are getting too worn for slush and snow.
Myth: All-wheel drive or 4WD means you can drive normally on snow.
Fact: AWD and 4WD help you get moving. They don’t help you stop or turn. Braking and steering grip come from the tires, so slow down and leave more room no matter what you drive.
Is it worth washing your car when the roads are salty?
Myth: There’s no point washing the car in winter because it’ll just get dirty again.
Fact: Maryland road crews use salt and brine to treat roads before and during storms. That salty spray coats the underside of your car, and salt speeds up rust on brake lines, fuel lines, exhaust parts, suspension components and the body. The paint is the least of it. The damage underneath is out of sight until something rusts through.
- Rinse the underside every so often during salty stretches, especially after a storm.
- Use a car wash with an underbody spray, or a hose if it’s warm enough.
- Pick a day above freezing so doors, locks and seals don’t freeze shut.
- Give the car a good wash when salt season ends in spring.
Rust underneath shows up in the shop as corroded brake lines, rusted-out exhaust and muffler parts, and seized hardware. Keeping the salt off slows all of that down.
What other winter car myths should you ignore?
“My battery started fine yesterday, so it’s fine.”
Batteries often fail without much warning, and cold weather is when a weak one gives out. Cold reduces the power a battery can deliver while making the engine harder to crank. If your battery is 3 years old or more, have it tested in the fall. Our guide to car battery care for Maryland winters covers testing, terminals and jump-starting.
“Plain water in the radiator is fine.”
Water freezes, expands and can crack the radiator, hoses or even the engine block. Coolant, usually mixed about 50/50 with water, protects against freezing and corrosion. Use the type your owner’s manual specifies, and never open the radiator cap on a hot engine. If you keep losing coolant, have the cooling system checked for leaks.
“Hot water is the fastest way to clear a frozen windshield.”
Pouring hot water on cold glass can crack the windshield, especially if there’s already a chip. Use the defroster, an ice scraper and a de-icer spray instead.
“A half tank of gas is only about frozen fuel lines.”
Frozen gas lines are uncommon in modern gasoline cars. Keeping the tank at least half full is still a smart winter habit, though. If you get stuck in traffic during a storm or stranded on the side of the road, you’ll have fuel to run the heater.
Get your car ready before the first freeze
We test batteries, alternators and starters so your car starts on the coldest Maryland mornings.
Winter car maintenance FAQ
How long should I warm up my car in winter?
For most modern cars, about 30 seconds to a minute is enough, then drive gently for the first several minutes. Take longer only if you need time to clear snow, ice and fog from the windows.
Should I let air out of my tires for snow?
No. Keep your tires at the pressure on the driver’s door sticker. Underinflated tires handle and brake worse.
Why does my tire pressure light come on when it’s cold?
Tire pressure drops as air gets colder, so a cold morning can push one or more tires below the warning point. Check and fill all four tires; if the light stays on, have the TPMS sensors checked.
Do I need snow tires in Maryland?
Many drivers in central Maryland get by with good all-season tires with plenty of tread. If you drive in every storm or travel to western Maryland in winter, winter or all-weather tires are worth considering.
How often should I wash road salt off my car?
There’s no fixed rule, but rinsing the underside every week or two during salty stretches, and after big storms, is a good habit. Pick a day above freezing so doors and locks don’t freeze.
Bring your car to New Level Auto Service
We’re at 716 E Gude Dr in Rockville, MD. Walk-ins are welcome, and calling ahead gets you in faster.
- Phone (301) 762-1200
- Hours Monday to Friday 8 AM to 5 PM, Saturday 9 AM to 2 PM
- Extras Night drop and 24-hour emergency towing