Winter Checklist for Used Cars: Preparation and Maintenance
Getting Your Vehicle Winter-Ready
Winter places special demands on your vehicle. With our comprehensive checklist, you can optimally prepare your BMW, Mercedes or Audi for the cold season.
The Most Important Checkpoints
Tires and Wheels
| Checkpoint | Target Value | Importance |
|---|---|---|
| Winter tire tread depth | Min. 4 mm (legal min. 1.6 mm) | Critical |
| Tire age | Max. 6-8 years | High |
| Air pressure | +0.2 bar over summer | Important |
| Spare tire/repair kit | Functional | Important |
Tip: For premium vehicles, investing in quality winter tires pays off. Recommendations:
- BMW: Original BMW winter wheels or brand tires (Michelin, Continental)
- Mercedes: Mercedes originals or Pirelli, Dunlop
- Audi: Audi original winter wheels for optimal Quattro performance
Battery
The battery is particularly stressed in winter:
| Checkpoint | Action |
|---|---|
| Voltage | Measure in cold (>12.4V) |
| Acid level | Check on serviceable batteries |
| Terminal clamps | Clean, apply terminal grease |
| Age | Replace preventively after 5-6 years |
Brand-specific:
- BMW: AGM batteries mandatory for start-stop vehicles
- Mercedes: Original battery recommended for SBC systems
- Audi: Quattro models need sufficient capacity
Lighting
| Element | Check |
|---|---|
| Low beam | Function and alignment |
| High beam | Function |
| Fog lights | Function (if equipped) |
| Rear fog light | Function |
| Turn signals | All four sides |
| Brake lights | Both + center high mount |
| Reverse light | Function |
| License plate lighting | Function |
Wipers and Visibility
| Checkpoint | Recommendation |
|---|---|
| Wiper blades | Replace before winter |
| Windshield washer fluid | Antifreeze to -30°C |
| Windows inside | Clean to prevent fogging |
| Side mirrors | Check heating function |
Fluids
| Fluid | Winter Requirement |
|---|---|
| Coolant | Check antifreeze to -25°C |
| Engine oil | Correct viscosity (0W-30/0W-40 for cold start) |
| Brake fluid | Water content <3% (check boiling point) |
| Power steering fluid | Check level |
Brand-Specific Winter Checks
BMW
E-Series (E38, E39, E46, E60, E90):
| System | Check |
|---|---|
| Cooling system | Expansion tank for cracks |
| Thermostat | Correct opening temperature? |
| Heater valve | Known issue on E46 |
| IHKA/IHKR | Climate control function |
Tip for E46 owners: The heater valve is a known wear part. Check if the heater warms up quickly.
Mercedes-Benz
W-Series (W140, W210, W211, W220):
| System | Check |
|---|---|
| Glow plugs | Pre-heat function on diesel |
| Air suspension | Function in cold |
| SBC brakes (W211) | Read fault memory |
| Sunroof | Clean drains |
Tip for W211 owners: The SBC brakes are sensitive to cold. Have the fault memory read before winter.
Audi
B5/C5/D2 Platforms:
| System | Check |
|---|---|
| Quattro drive | Haldex oil on newer models |
| Turbocharger | Allow warm-up time at cold start |
| Intercooler | Check for leaks |
| Glow plugs | Function on TDI engines |
Tip for Quattro drivers: Despite AWD, winter tires are mandatory! Quattro improves traction, not braking distance.
Emergency Equipment
Recommended Basic Equipment
| Item | Purpose |
|---|---|
| Ice scraper + hand brush | Clear windows |
| Jumper cables | Enable outside assistance |
| Warning triangle | Legally required |
| Warning vest | Legally required |
| Flashlight | Emergency in darkness |
| Blanket | Warmth during breakdown |
Extended Equipment
| Item | Recommendation |
|---|---|
| Snow chains | For mountain driving |
| Folding shovel | Stuck situations |
| De-icer spray | For door locks |
| Gloves | Working on vehicle |
Maintenance Costs Overview
Typical Winter Preparation
| Service | Price Range |
|---|---|
| Winter tire change | €30-60 |
| Battery test | €15-30 (often free) |
| Coolant check | €20-40 |
| Complete winter check | €80-150 |
Common Winter Repairs
| Repair | BMW | Mercedes | Audi |
|---|---|---|---|
| Battery replacement | €200-400 | €250-500 | €180-350 |
| Glow plugs (diesel) | €150-300 | €180-350 | €150-280 |
| Heater valve | €150-250 (E46) | - | - |
| Thermostat | €120-250 | €150-300 | €130-250 |
Long-Term Winter Storage
If you’re storing your vehicle over winter:
Preparation
- Fill up: Full tank (prevents condensation)
- Oil change: Fresh oil before storage
- Battery: Disconnect or connect trickle charger
- Tires: Increase air pressure or put on jack stands
- Parking brake: Release (prevent seizing)
Ideal Storage Conditions
| Factor | Recommendation |
|---|---|
| Temperature | 5-15°C, constant |
| Humidity | <60% |
| Ventilation | Adequate |
| Cover | Breathable |
Conclusion
Thorough winter preparation protects your vehicle and maintains its value. Especially with older premium vehicles, investing in preventive maintenance pays off. Plan your winter check in time – ideally in November before the first frost arrives.
Drive safely through winter!
All price information are approximate values and may vary by region and workshop.