Which Coolant to Choose in Unstable Weather Conditions?

Unstable Weather Demands a Special Approach: Not “Just to Prevent Freezing,” but “To Prevent Degradation During Temperature Swings”

March is the most deceptive month for the cooling system. The sun warms up, snow melts, and it seems winter is over. But outside, nighttime frosts can still reach –18 °C, while daytime temperatures rise to +7 °C. These daily swings of 25 degrees are the main enemy of low-quality coolant.

The issue isn’t just whether the fluid will freeze. Far more dangerous is its thermal instability. Cheap formulations based on low-grade ethylene glycol lose their homogeneity after repeated freeze-thaw cycles. Corrosion inhibitors precipitate out, water crystallizes, and the base turns into a gel. Even if the engine starts, the protection is already gone.

How to Choose a Coolant That Can Handle March Weather?

Rule #1: Check the freezing point of the ready-to-use fluid.

If you buy a concentrate (e.g., CHEMIPRO G12+), you need to dilute it with water in a 1:1 ratio.

→ The resulting solution will have a freezing point of –37 °C.

If you buy a ready-to-use fluid (e.g., CHEMIPRO G11), it already has the specified freezing point (e.g., –35 °C).

Don’t be confused: a label saying «–40 °C» on a concentrate refers to the undiluted product, not the working solution.

Rule #2: Choose by class, not by color.

For example, G12+ (red) is for most vehicles manufactured between 2008 and 2018 (VW, Skoda, Audi, BMW, Ford).

Color is marketing. The class determines technical compatibility.

Rule #3: Consider not just the minimum temperature, but also the number of cycles.

High-quality coolant based on Organic Additive Technology (OAT) remains stable even after 50+ cycles of “–20 °C ↔ +10 °C”. Cheap alternatives often break down after just 5–7 such fluctuations.

CHEMIPRO Recommendations for March Weather

For most passenger cars (VW, Skoda, Hyundai, Kia, Renault):

→ CHEMIPRO G12+ Red (concentrate) / [CH 083, CH 084, CH 140, CH 182, CH 183]

• Dilute 1:1 with distilled water.
• Get protection down to –37 °C.
• Service life: 5 years / 250,000 km.

For modern cars with turbocharging and complex cooling systems (BMW, Mercedes, Audi, 2015+ models):

→ CHEMIPRO G12 EVO Purple (ready-to-use) / [CH 155, CH 154]

• Ready to pour – no dilution required.
• Freezing point: –35 °C.
• Environmentally friendly formula, compatible with aluminum and plastic components.

Why Right Now Is the Best Time for a Change?

• Coolant added in March will undergo a “break-in” period under fluctuating conditions and prove its stability before summer arrives.
• You’ll avoid spring overheating caused by clogged channels from degraded old coolant.
• Prices for quality products are lower than the peak summer prices – it’s a cost-effective solution.
• Don’t chase the “cheapest option.” Aim for stability.