Preparing Your BMW for Winter

Cold weather is hard on BMWs. Plastic cooling components get brittle, batteries lose capacity, and rubber seals shrink. Here's how to winterize properly.

Battery

Cold reduces battery capacity by up to 35% at -18°C. A battery that barely starts the car in summer will fail in winter.

• Test your battery before winter — any auto parts store does this free
• Replace if older than 4-5 years — don't gamble
• Keep it charged — short trips don't fully recharge. Use a trickle charger if the car sits.
• Clean terminals — corrosion increases resistance

Coolant

• Check the coolant concentration — should be 50/50 antifreeze/water
• 50/50 mix protects to approximately -37°C
• Use a refractometer or test strips to verify
• If the coolant is old or brown, flush and replace
• Never use pure water — it freezes and cracks the engine block

Oil

• Switch to a lower viscosity if you're in extreme cold: 0W-30 or 0W-40
• Thinner oil flows faster on cold starts, protecting the engine sooner
• BMW LL-01 0W-30 is ideal for winter

Tires

• Winter tires are not optional in cold climates. All-seasons are a compromise.
• Summer tires become rock-hard below 7°C — they have almost no grip
• Winter tires have softer compounds and siping for snow/ice traction
• Popular choices: Michelin Pilot Alpin, Continental WinterContact, Bridgestone Blizzak
• Consider a dedicated set of winter wheels (cheaper steel wheels protect your alloys from salt)

Wipers & Washer Fluid

• Replace wiper blades if they streak
• Fill washer fluid with winter-rated fluid (-20°C or lower)
• Never use water in the washer reservoir — it freezes and cracks the reservoir and lines

Lights

• Check all lights — days are shorter, visibility matters
• Clean headlight lenses — salt spray reduces light output
• Carry spare bulbs if your car uses replaceable bulbs

Undercarriage

• Apply undercarriage wax or rust protection before winter
• Road salt is the #1 cause of BMW rust
• Wash the undercarriage regularly during winter (touchless car wash with undercarriage spray)

Emergency Kit

Keep in the trunk:

• Jumper cables or lithium jump pack
• Blanket
• Flashlight
• Ice scraper and snow brush
• Small shovel
• Traction mats or cat litter (for getting unstuck)
• Phone charger