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BMW requires nitrate-free and phosphate-free ethylene glycol-based coolant meeting either the G48 or HT-12 specification[1]. For most BMWs built before 2018, use G48 coolant (blue). For 2019 and newer models, use HT-12 coolant (green)[2]. HT-12 is backward compatible with G48, but G48 should not be used in vehicles originally filled with HT-12[3].
BMW Coolant Types: G48 vs HT-12
BMW uses two main coolant specifications. Understanding the difference prevents costly mistakes.
| Specification | Color | Model Years | Part Number | Change Interval |
|---|---|---|---|---|
| G48 (LC-87) | Blue | Pre-2018 | 83192211194 | 4 years |
| HT-12 (LC-18) | Green | 2019+ | 83195A42DF3 | 2 years |
BMW part numbers may vary by region[1][2]
Both coolants are HOAT (Hybrid Organic Acid Technology) formulations supplied as concentrates requiring dilution with distilled water[4]. The standard mix ratio is 50/50 coolant to water, providing freeze protection to -37°C (-34°F) for G48 and -34°C (-29°F) for HT-12[4].
Can You Mix BMW Blue and Green Coolant?
Yes, but only in one direction. HT-12 (green) is compatible with G48 (blue) and can be added to vehicles that originally contained blue coolant[3]. The reverse is not recommended—don’t add blue G48 to vehicles designed for HT-12[2].
If you accidentally added a small amount of blue coolant to a 2019+ BMW that requires green, the system won’t immediately fail. But plan a complete coolant flush at your next service interval to restore the proper HT-12 chemistry[5]. Understanding BMW maintenance costs helps budget for these situations.
Why BMW Requires Specific Coolant
BMW engines use significant aluminum components in radiators, water pumps, and engine blocks. Standard automotive coolants containing nitrates or phosphates cause corrosion and deposit formation on these aluminum parts[1].
BMW-approved coolants are specifically formulated to:
- Protect aluminum, cast iron, and steel components
- Prevent harmful deposit formation
- Reduce excessive silicate gel precipitation that can clog passages
- Provide corrosion inhibition for all cooling system metals[3]
Generic green coolant from auto parts stores typically contains phosphates and won’t meet BMW specifications—even if it’s labeled “for all makes and models”[1]. The catch? Using incompatible coolant may void warranty coverage for cooling system failures.
BMW-Approved Coolant Alternatives
You don’t have to buy from the dealer. Several aftermarket coolants meet BMW specifications.
G48 Specification (Blue) Compatible
- BASF Glysantin G48 – The original OEM manufacturer for BMW[6]
- Pentosin NF Antifreeze – Available at NAPA auto parts stores[7]
- Zerex G-48 – Widely available aftermarket option[7]
- BMW Genuine Antifreeze (Part# 83192211194)
HT-12 Specification (Green) Compatible
- BMW Genuine HT-12 (Part# 83195A42DF3)
- Aftermarket HT-12 options are less common—dealer purchase recommended for 2019+ vehicles
When purchasing alternatives, verify the product explicitly states “G48” or “HT-12” compatibility. Generic “European formula” coolants don’t necessarily meet BMW’s nitrate-free and phosphate-free requirements[1].
BMW Coolant by Model Year
Knowing your vehicle’s model year determines which coolant to use.
| Model Year | Required Coolant | Color | Notes |
|---|---|---|---|
| 2018 and older | G48 | Blue | Can upgrade to HT-12 |
| 2019–present | HT-12 | Green | Don’t use G48 |
| Electric (i3, iX, i4) | Check manual | Varies | May have different requirements |
Always verify with your owner’s manual[2]
BMW transitioned to HT-12 around 2018–2019, but the exact cutoff varies by model. Some 2018 models shipped with HT-12, while others used G48[2]. Check the coolant reservoir—green or blue color indicates which type is currently in your system.
If you’re maintaining an older BMW like an E90 with the N52 engine, G48 remains the appropriate choice. These engines are particularly sensitive to coolant chemistry due to their magnesium-aluminum composite blocks.
How Much Coolant Does a BMW Need?
BMW cooling systems hold approximately 7–12 liters (1.8–3.2 gallons) depending on the model and engine[8].
| Model | Approximate Capacity |
|---|---|
| BMW 3 Series (F30/G20) | 7–8 liters |
| BMW 5 Series (G30) | 8–10 liters |
| BMW X3 (G01) | 7–9 liters |
| BMW X5 (G05) | 10–12 liters |
Capacities vary by engine variant
For a complete coolant flush and refill, purchase 4–6 liters of concentrate plus distilled water for mixing, or 8–12 liters of pre-mixed 50/50 coolant[8]. Minor top-offs require only 0.5–1 liter. If you frequently need top-offs, check for leaks—cooling systems are sealed and shouldn’t lose significant fluid under normal conditions[3].
How to Check BMW Coolant Level
BMW cooling systems use a pressurized expansion tank. Never open the cap when the engine is hot—wait at least 30 minutes after driving.
- Park on level ground with the engine cool
- Locate the expansion tank (usually near the firewall)
- Check the fluid level against MIN/MAX markers
- Coolant should be between markers when cold
- If low, add the correct type in small increments[8]
On newer BMWs, the coolant level displays digitally through the iDrive system. A persistent low coolant warning after topping off indicates a leak requiring diagnosis. Check expansion tank seams first—these are a known failure point[3].
BMW Coolant Flush Cost
Professional coolant flush costs vary by model and location.
| Service Type | Average Cost (US) | Average Cost (UK) |
|---|---|---|
| Coolant Change | $292–$372 | £51–£166 |
| Full Flush | $350–$500 | £80–£200 |
| DIY Parts Only | $50–$100 | £40–£80 |
Based on BMW 328i/3 Series estimates[8][9]
BMW recommends coolant replacement every 4 years or 50,000 miles for G48, and every 2 years for HT-12[10]. Skipping this service leads to degraded corrosion protection and potential overheating issues. For related maintenance, see what type of oil your BMW 328i requires.
Coolants to Avoid in BMW
Never use these coolant types in any BMW:
- Universal “all makes” coolant – Usually contains phosphates
- Dex-Cool (orange) – GM specification, not compatible
- IAT (green automotive) – Contains silicates that damage BMW seals
- Any coolant with nitrates or phosphates – Corrodes aluminum
- Tap water for mixing – Mineral content causes deposits[1]
Using incompatible coolant causes silicate gel precipitation, which clogs small passages in the radiator, heater core, and engine block[4]. Damage may not appear immediately but accumulates over time.
Key Takeaways
- BMW requires nitrate-free, phosphate-free coolant meeting either G48 (blue, pre-2018) or HT-12 (green, 2019+) specifications—generic automotive coolant will damage aluminum components[1].
- HT-12 green coolant is backward compatible with G48 blue, but blue G48 should not be used in vehicles originally filled with HT-12[3].
- BASF Glysantin G48, Pentosin NF, and Zerex G-48 are approved alternatives to dealer-purchased BMW coolant for older vehicles[6][7].
- Coolant change intervals are 4 years for G48 and 2 years for HT-12—professional flush costs $292–$372 for most models[8][10].
- Always mix concentrate with distilled water at 50/50 ratio; tap water mineral content causes harmful deposits in the cooling system[4].
FAQs
Can I use Prestone in my BMW?
Only if it’s the Prestone European Formula that meets G48 specifications. Standard Prestone contains silicates and phosphates not approved for BMW. Always verify the product states “nitrate-free” and “phosphate-free” with G48 or HT-12 compatibility[1].
How often should BMW coolant be changed?
For G48 (blue) coolant: every 4 years or 50,000 miles. For HT-12 (green) coolant: every 2 years[10]. HT-12’s shorter interval reflects its different additive package, not inferior quality.
Why is my BMW coolant green instead of blue?
If your BMW is 2019 or newer, green HT-12 coolant is correct. If it’s an older model, someone may have upgraded from G48 to HT-12 (which is acceptable) or used non-BMW coolant (which should be verified)[2].
Is BMW coolant the same as Mercedes coolant?
No. Mercedes uses different coolant specifications. BMW’s G48 and HT-12 are not interchangeable with Mercedes-Benz 325.0 or 325.5 specifications. Each manufacturer formulates coolant for their specific engine materials and seal compounds.
Can I use water temporarily if I run out of coolant?
In an emergency, distilled water can top off a small amount. But straight water provides no freeze protection and minimal corrosion protection[4]. Replace with proper coolant mixture as soon as possible.
References
-
Scrap Car Comparison. (2025). What Coolants to Use in a BMW, and How to Top It Up.
What coolants to use in a BMW, and how to top it up
- xBimmers Forums. (2025). Dealership Filled Car with Blue Coolant Discussion. https://x3.xbimmers.com/forums/showthread.php?t=2207876
- BimmerPost F80 Forums. (2020). Coolant is Green and Need to Top It Off? https://f80.bimmerpost.com/forums/showthread.php?t=1768046
- YouTube. (2022). Blue Coolant (LC-87) vs Green Coolant (LC-18 a.k.a. HT-12).
-
Reddit r/BMW. (2023). Just Put Blue Coolant in My 2019 X3 Discussion.
Just put Blue coolant in my 2019 X3.. how screwed am I?
byu/nyknicks23 inBMW - Bimmerforums. (2013). BMW Approved Coolants Discussion. https://www.bimmerforums.com/forum/showthread.php?1953757-BMW-Approved-Coolants
-
Reddit r/MechanicAdvice. (2019). Do I Really Need BMW Coolant?
Do I really need BMW coolant? The nearest dealership is 90 minutes away.
byu/ImHadn inMechanicAdvice - RepairPal. (2024). BMW 328i Coolant Change Cost Estimate. https://repairpal.com/estimator/bmw/328i/coolant-change-cost
- Fixter UK. (2024). BMW Engine Coolant Flush & Replacement Costs. https://www.fixter.co.uk/engine-coolant-flush/bmw
- Kelley Blue Book. (2024). BMW Coolant Flush Prices & Cost Estimates. https://www.kbb.com/bmw/coolant-flush/
I am a senior automotive analyst at Autvex. Expert vehicle evaluations, in-depth reviews, and objective analysis helping readers make informed automotive decisions with years of industry experience.
