Winter brings more than snow and ice, it brings strain. Low temperatures test every system in your fleet, from batteries and air dryers to tires and fuel lines. Without proper preparation, those small seasonal shifts can quickly cascade into safety risks and costly downtime.
To help fleets prepare, here are five areas to focus on before the thick of winter hits—and even continue throughout the season.
BATTERIES AND ELECTRICAL SYSTEMS
Cold weather is a battery’s toughest test. Low temperatures slow chemical reactions inside the battery, reducing its output. Weak batteries that perform well in the fall can fail suddenly once winter arrives.
Perform load tests, clean terminals, and verify that charging systems maintain proper voltage. For electric fleets, precondition batteries and confirm that heaters are operating efficiently. Electrical weaknesses can cause costly—and even dangerous—breakdowns, which is why it’s critical to identify and prevent these issues early.
AIR DRYERS AND BRAKE SYSTEMS
Frozen air systems are among the most common, and preventable, winter vehicle failures. Moisture builds up, and if it’s not drained regularly, in the winter, that water freezes and immobilizes the vehicle.
Inspect and service air dryers according to OEM recommendations, replace cartridges when due, and make daily draining a standard operating procedure. A few minutes of attention in the yard can save hours of roadside downtime when the temperature drops below freezing.
TIRES AND FUEL SYSTEMS
Tires remain the top cause of roadside events year-round, and winter introduces new risks. FleetNet America by Cox Automotive data shows tires lead roadside breakdowns (accounting for 31 to 43 percent of events), followed by brakes, electrical, and towing failures. The consistency of these issues, year after year, proves one thing: preventive maintenance isn’t just important—it’s essential to keeping vehicles on the road when the temperature falls.
Tire pressure can drop 10 to 15 percent in cold weather, increasing the likelihood of blowouts and irregular wear. Before winter, check tread depth, adjust inflation for lower temperatures, and rotate tires as needed.
Fuel systems also require seasonal attention. Verify the use of winter-grade or blended fuels and confirm that anti-gel additives are approved for each vehicle’s engine type. Test fuel heaters and replace filters before the first freeze to prevent gelling and ensure proper flow.
COOLING SYSTEMS AND ENGINE HEALTH
Cooling system issues can lead to engine shutdowns, underscoring that proper performance is critical to avoid costly breakdowns. Check that antifreeze is properly mixed and that block heaters are functional. Pressure-test the system to identify leaks and inspect all belts and hoses for wear or brittleness.
Road grime on a vehicle can be a year-round headache, but in the winter, it can add extra hours to repair time if a vehicle is down. Clean radiators and remove salt or debris to prevent airflow blockages. Even in winter, restricted airflow can lead to overheating or reduced engine efficiency.
DRIVER SAFETY AND PREPAREDNESS
A prepared fleet includes prepared drivers. Equip each cab with cold-weather essentials such as blankets, flashlights, jumper cables, non-perishable food, and water. Confirm that windshield wipers, washer fluid, defrosters, and heated mirrors are all in working order.
Encourage drivers to complete thorough pre- and post-trip inspections and to understand local frost laws and idling restrictions before traveling into colder regions. Small oversights can quickly escalate into safety risks when visibility, traction, and temperature combine.
STAY READY, STAY MOVING
Winter’s challenges are unavoidable, but costly breakdowns aren’t. Relentless, year-round maintenance and prompt attention to even minor issues are your fleet’s best defense. By making thorough winter checks a non-negotiable part of your routine, you’ll slash downtime, maximize vehicle lifespan, and—most importantly—protect your drivers, no matter how brutal the weather becomes.
SAFETY TIPS
- Never attempt to jumpstart a frozen battery, ice expansion can cause it to become flammable and explode.
- Don’t overlook the brake system until it’s frozen. Routine draining and cartridge replacement are far cheaper than a roadside service call.
- Properly inflated tires and treated fuel keep your fleet moving when temperatures fall below zero.
- Cold weather doesn’t eliminate heat issues, blocked radiators can still cause temperature spikes in winter.
- Frost laws set seasonal weight restrictions on roads during the winter and spring thaw. Drivers should heed roads posted with weight limits that reduce the maximum legal weight per axle.
about the author
Jeff Greenwell is the senior vehicle services trainer, Fleet Services by Cox Automotive, and Mike Hagaman is the senior manager, client relationship management, FleetNet America by Cox Automotive.
