Many car owners encounter a frustrating problem in winter – their cars suddenly won't start on cold mornings.
This article will explain the real reasons for starting difficulties in winter from multiple perspectives, including battery, engine oil, fuel system, and engine characteristics, and provide practical solutions.
1. Battery Performance Drops Significantly at Low Temperatures
1.) Low temperatures cause a sudden drop in battery capacity of 20%–50%.
Both lead-acid and lithium batteries share a common characteristic: the lower the temperature, the lower the battery's activity and the lower the output current.
Battery performance is optimal at 25℃.
Capacity drops by approximately 20% at 0℃.
Capacity drops by 40%–50%+ at -10℃ to -20℃.
When the battery cannot provide sufficient instantaneous current (Cold Cranking Amps, CCA), the engine cannot ignite properly.
2.) Older batteries are more prone to failure in winter.
Batteries older than 2-3 years are more likely to experience the following issues in winter:
Unstable voltage
Insufficient cold start current
Accelerated discharge rate.
2. Engine oil thickens.
The effects of thickened engine oil in winter:
Increased engine resistance
Higher current required by the starter motor
Double battery load, leading to faster battery drain.
Higher grade oils (e.g., 10W-40, 15W-40) are even more difficult to start in cold weather.
0W or 5W oils with better low-temperature fluidity are recommended for winter use.
3. Poor Fuel Atomization
Gasoline Vehicles:
Incomplete atomization
Incomplete ignition
Difficulty starting in cold weather
Diesel Vehicles:
Diesel fuel waxing at low temperatures
Fuel line blockage
Difficulty starting or even complete failure to start
4. Engines Require More Energy to Start in Cold Weather
Starting an engine in a cold state requires:
More fuel, stronger current, and faster crankshaft rotation
5. Common Signs of Cars Difficult to Start in Winter
Continuous "ticking" sound during ignition
Dim dashboard lights
Slow starter motor rotation
Failure to start after multiple attempts
Completely unresponsive after parking overnight
These are typical signs of a dead battery or overly thick engine oil.
6. How to Reduce Starting Difficulties in Winter?
1.) Regularly check the battery, paying extra attention to its health in winter.
2.) Use engine oil with good low-temperature fluidity (e.g., 0W-20 / 5W-30).
3.) Fill up with winter-grade fuel in cold regions.
4.) Park in a warm, enclosed location whenever possible.
5.) Use a jump starter.
7. What to do if your car won't start in winter?
If your car won't start in winter, don't panic. Follow these steps to troubleshoot and try to restart it. These methods are simple and practical, suitable for ordinary car owners to handle themselves on the roadside, in a garage, or outdoors.
1.) First, check the battery status.
If the dashboard lights are dim and you only hear a "clicking" sound when starting, the battery is low on power.
You can try:
Turning off the air conditioning, lights, and audio system.
Try starting the ignition again.
If it starts, drive for 20-30 minutes to charge the battery.
2.) Use a jump starter.
In winter, carrying a jump starter is the most effective solution.
The usage is very simple: Open the hood. Plug the red clip of the emergency starter into the positive terminal of the battery and the black clip into the negative terminal. Turn on the starter. Return to the car and start the engine normally. Once the engine starts, remove the clips.
No need to wait for roadside assistance, no jumper cables, and no other vehicle required.
