What Coolant Is Best for a BMW 4 Series?

The correct coolant for a BMW 4 Series is a BMW-approved, phosphate- and nitrite-free HOAT (Hybrid Organic Acid Technology) coolant, typically the blue BMW OEM coolant concentrate mixed 50:50 with distilled water; using the wrong coolant can damage the engine, cooling system, and void warranty coverage. This article explains which coolant types are approved, how to identify the right product, mixing ratios, and key maintenance tips owners should follow.

Understanding BMW’s Coolant Requirements

BMW engines, including those in the 4 Series (F32/F33/F36, G22/G23/G26, and newer), are engineered to run with very specific coolant chemistry that protects aluminum components, seals, and plastic fittings while resisting corrosion and deposits over a long service life.

BMW’s Own Specification

BMW does not simply use generic “green” or “universal” antifreeze. Instead, it specifies an ethylene-glycol based coolant that is:

• Phosphate-free
• Amines-free
• Nitrate/nitrite-free
• Silicate-reduced or silicate-free (depending on generation)
• Formulated as HOAT (Hybrid Organic Acid Technology), not basic IAT (old green) or pure OAT (Dex-Cool–type)

These chemical requirements are designed to ensure long-lasting corrosion protection for BMW’s predominantly aluminum engines and radiators, as well as compatibility with modern plastics and gaskets used across the 4 Series range.

The Recommended Coolant for BMW 4 Series Models

BMW 4 Series models—from early F32/F33/F36 (2013–2020) through current G22/G23/G26 generations—share essentially the same coolant requirement: an approved BMW coolant (blue) mixed correctly with distilled water.

Official BMW OEM Coolant

The primary recommendation for any BMW 4 Series in most markets is the factory-branded coolant sold by BMW dealers and many independent European parts suppliers.

The key characteristics of BMW’s OEM coolant are:

• Color: Typically light blue
• Type: HOAT, specially formulated for BMW aluminum engines
• Format: Usually sold as concentrate, not premixed
• Typical part numbers (may vary by region and packaging):
  

  • 82 14 2 209 769 – BMW Antifreeze/Coolant (1 gallon/3.78 L concentrate, North America)
  • 83 19 2 211 191 or superseding numbers – similar BMW Group blue coolant in EU and other regions

Owners should note that packaging and part numbers change periodically, but if it is sold as BMW-branded antifreeze/coolant for current models and is blue, it is typically the correct product for the 4 Series.

Mixing Ratio: Coolant and Water

Because BMW coolant is usually sold as concentrate, it must be mixed with distilled water before filling or topping off the cooling system.

For a BMW 4 Series in normal climates, BMW and most specialists recommend:

• 50:50 mix – 50% BMW coolant concentrate and 50% distilled water
• Freeze protection: Approximately down to around −35°C (−31°F)
• Boil protection: Improved over plain water, especially under system pressure

This 50:50 mixture balances freeze protection, boil protection, and corrosion resistance, making it appropriate for almost all everyday driving conditions.

Approved Aftermarket Alternatives

While OEM BMW coolant is the safest choice, some high-quality aftermarket options are formulated to meet or closely match BMW’s chemical requirements for modern 4 Series engines.

Coolant Brands Commonly Used in BMWs

Several European-focused coolant brands produce products that are explicitly labeled as compatible with BMW specifications. Even then, careful label-checking is crucial.

Common BMW-compatible aftermarket coolants (as of late 2024) include:

• PEAK "European Vehicle" Blue (for BMW) – Formulated to meet BMW HOAT requirements; check the specific label for “BMW” or “for European blue coolant”.
• Prestone European Vehicle (Blue) – Marketed in some regions as suitable for BMW, Mercedes-Benz, and other European brands; ensure the label mentions BMW compatibility.
• RAVENOL HJC or equivalent BMW-approved coolants – Some European brands explicitly list BMW among their approvals.
• Febi Bilstein / Mahle / Zerex G-48 (where available) – Certain G-48–type coolants are known to be BMW-compatible, though you must confirm the current spec and labeling.

Even when using these products, experts generally caution against mixing multiple brands or types; ideally, use them only when fully flushing and refilling the system, not simply topping off an unknown mixture.

Coolants You Should Avoid in a BMW 4 Series

Using the wrong coolant can create sludge, reduce corrosion protection, shorten the life of water pumps and radiators, and lead to overheating or internal damage, all of which are more costly than purchasing the correct fluid in the first place.

Incompatible or Risky Coolant Types

Several common antifreeze types are not suited to BMW 4 Series engines and should be avoided.

Key coolant types to avoid include:

• Traditional "green" IAT coolant – Older silicate-heavy formulas designed for 20th-century cast-iron engines and brass radiators; not ideal for modern BMW aluminum systems.
• Dex-Cool–style OAT (often orange) – Common in some North American vehicles; chemistry differs from BMW’s HOAT and can cause issues if mixed.
• Generic "universal" all-makes-all-models coolant – Often aims to be compatible with many systems but may not strictly match BMW’s requirements; labels can be vague.
• Coolant containing phosphates or nitrites – Risk of scale formation and corrosion in BMW’s aluminum-heavy cooling systems.
• Random color matching without spec verification – Color alone is not a reliable indicator of chemistry; always check specifications and approvals.

How to Top Off Coolant Safely on a BMW 4 Series

Many owners only interact with the cooling system when a low coolant warning appears or when checking fluids in the engine bay; topping off incorrectly, however, can introduce incompatibilities and air into the system.

Basic Topping-Off Procedure

The goal when topping up is to maintain the proper mixture and chemistry while avoiding air pockets that can lead to hot spots or overheating.

The general steps most experts recommend (always cross-check with your BMW owner’s manual) are:

1. Check engine temperature: Allow the engine to cool fully before opening the coolant expansion tank; opening when hot can cause scalding steam or fluid release.
2. Locate the expansion tank: On most 4 Series models, this is near the radiator, with a black plastic cap labeled with a warning symbol.
3. Inspect the level indicator: Many tanks have a float or mark indicating “cold” level; read this only when the engine is cool.
4. Prepare the mixture: Pre-mix BMW blue coolant concentrate with distilled water at 50:50, or use a BMW-approved pre-mixed product.
5. Add slowly: Pour the mixture into the tank until the float or level mark reaches the recommended “cold” line; avoid overfilling.
6. Reinstall the cap securely: Tighten the cap, ensuring it is fully seated to maintain correct system pressure.
7. Monitor after driving: After one or two drives, re-check the level when the engine is cool to confirm stability.

Following these steps reduces the risk of sudden pressure release, air lock, or incorrect coolant ratios, especially critical with turbocharged 4 Series engines that run hot under load.

Flushing and Replacing Coolant

Although BMW often promotes “lifetime” fluids in marketing, independent specialists and many owners prefer periodic coolant changes for 4 Series models to maintain optimal corrosion protection and system cleanliness.

Recommended Change Intervals

Intervals can vary by region and model year, but a conservative approach widely suggested by independent BMW technicians is:

Typical coolant replacement intervals:

• Every 4–5 years or about 80,000–100,000 km (50,000–60,000 miles)
• Sooner if:
  

  • Coolant appears rusty, cloudy, or discolored
  • Cooling system components (radiator, water pump, hoses) have been replaced
  • A previous owner may have used an unknown or incorrect coolant

Replacing the coolant on this schedule helps preserve the head gasket, turbocharger cooling circuits, and plastic fittings notorious for aging in BMW cooling systems.

Professional vs. DIY

Flushing the coolant on a modern BMW 4 Series is more complex than on older cars because of electric water pumps, electronic thermostats, and specific bleed procedures.

Key considerations when deciding between DIY and professional service include:

• Bleeding procedure: Many 4 Series engines require a specific electronic bleed cycle using the ignition and climate controls, or a diagnostic tool, to purge air.
• Proper disposal: Used coolant is toxic and must be disposed of at an appropriate recycling facility.
• System access: Draining requires opening the radiator drain (if present) or removing lower hoses, sometimes combined with engine block drains.
• Warranty and documentation: For late-model cars under warranty, using a BMW dealer or BMW-certified shop can simplify any future claims involving the cooling system.

Because of these factors, many 4 Series owners opt for professional service when doing a full flush, while reserving DIY work for simple level checks and top-offs with the correct coolant mixture.

Model-Specific Notes Across the 4 Series Range

While the broad coolant requirement is consistent, some nuances exist across the different generations and powertrains available in the BMW 4 Series lineup.

F32/F33/F36 (2013–2020)

The first-generation 4 Series—with engines such as the N20/N26 (428i), B48 (430i), N55 (435i), B58 (440i), and diesels in some markets—relies heavily on the blue BMW HOAT coolant, with electric water pumps and plastic expansion tanks.

For these models, owners should be aware of:

• Sensitivity to overheating: Turbocharged engines can suffer quickly if cooling is compromised.
• Ageing plastic components: After 8–10 years, coolant system plastics (expansion tank, connectors) become more brittle, making correct coolant and pressure critical.
• Electric pump behavior: The pump and thermostat are electronically controlled, so a correct bleed is vital after coolant service.

Proper coolant choice and regular checks are especially important on aging F-series cars to avoid unexpected failures linked to thermal stress.

G22/G23/G26 and Newer (2020–present)

The newer generation 4 Series models, including M440i, 430i, and the Gran Coupé variants, maintain similar coolant requirements while adding more complex cooling strategies, particularly for high-output mild-hybrid and performance variants.

Key points with the newer generation include:

• Even tighter temperature management: More electronics, turbocharging, and emissions controls rely on stable coolant temperature.
• Warranty considerations: For vehicles still under factory warranty, using non-approved coolant can create disputes if cooling-related issues emerge.
• Potential for multiple cooling circuits: Some models may have separate circuits for the engine, intercooler, or electronics, increasing the importance of correct fluid and bleeding.

Because of these complexities, sticking with BMW-branded coolant and following BMW’s service instructions is especially important on late-model G-series cars.

Signs of Coolant Problems in a BMW 4 Series

Although modern 4 Series dashboards will typically display a low-coolant warning, there are other subtle signs that the cooling system or coolant type might not be correct.

Warning Indicators and Symptoms

Recognizing early signs of cooling system issues can prevent more serious damage, particularly to turbocharged powertrains and cylinder heads.

Symptoms that may indicate coolant-related trouble include:

• Low coolant level warnings that recur shortly after topping up
• Visible leaks around the expansion tank, radiator, hose junctions, or water pump housing
• Discolored or sludgy coolant (brown, milky, or with particles) in the expansion tank
• Sweet smell from the engine bay or through the vents, indicating a coolant leak
• Overheating alerts or sudden jumps in temperature gauge/indicator
• White exhaust smoke when warm, combined with coolant loss, which can indicate internal leaks like head gasket issues

If any of these signs occur, especially in combination, it is advisable to have the car inspected promptly, as continued driving with cooling issues can result in significant engine damage.

Environmental and Safety Considerations

Coolant is not only critical for the car but also hazardous if mishandled. BMW 4 Series owners should be aware of basic safety measures whenever handling antifreeze.

Handling and Disposal

Ethylene glycol–based coolants, including BMW’s OEM product, are toxic if ingested and harmful to pets and wildlife, requiring careful containment and disposal.

Safe handling practices include:

• Keep away from children and animals: Even small amounts can be dangerous due to its sweet taste and toxicity.
• Wear gloves and eye protection when working with coolant to avoid skin and eye irritation.
• Use closed containers for storing new and drained coolant; never leave open pans unattended.
• Dispose of used coolant at authorized recycling or hazardous waste facilities; do not pour it down drains or on the ground.
• Clean spills immediately with absorbent material and dispose of it according to local regulations.

Taking these precautions protects not only personal safety but also the environment, while keeping the working area around your BMW 4 Series clean and safe.

Summary

BMW 4 Series models, from the early F32 generation to the latest G22 and beyond, are designed to run on a specific type of blue HOAT coolant that is phosphate- and nitrite-free and tailored for modern aluminum engines. The safest and most straightforward choice is BMW’s own OEM blue coolant, mixed 50:50 with distilled water, and used consistently throughout the system. While a few aftermarket coolants are formulated to meet BMW requirements, indiscriminate use of “universal,” green, or Dex-Cool–style fluids can lead to corrosion, deposits, and costly damage.

Routine checks, careful topping-off with the correct mixture, and periodic full replacements—ideally every four to five years—help safeguard the complex cooling systems and turbocharged powertrains that define the BMW 4 Series. Paying attention to coolant quality, level, and any early signs of leaks or overheating is a relatively small investment that preserves performance, reliability, and long-term engine health.

What coolant for BMW 440i?

HT-12 Antifreeze/Coolant • Exclusively formulated for BMW Group. Free of phosphates, nitrites, amines and borates.

Is BMW coolant green or blue?

BMW uses both green and blue coolants depending on the model year; blue coolant (G48cap G 48𝐺48) was standard on older models, while newer BMWs made from March 2018 onwards use green coolant (HT−12cap H cap T minus 12𝐻𝑇−12). The two coolants are technically backward-compatible, meaning you can use green in older cars, but BMW advises against mixing them due to the risk of a reaction and potential engine damage. The safest practice is to stick with the color that came in your car from the factory.
 
This video explains the differences between BMW blue and green coolants: 1mNoBrainer TalkYouTube · Mar 20, 2022
Coolant color guide

• Blue: The traditional BMW coolant, known as G48, was used in models made before March 2018. 
• Green: The newer coolant, known as HT-12, was introduced for models made after March 2018 and is also backward-compatible with older BMWs. 

Key considerations

• Avoid mixing: Do not mix blue and green coolants. If your car originally came with blue coolant, it’s best to continue using blue. If it came with green, continue using green. 
• Flush the system: If you need to change the type of coolant, you must completely flush the old coolant and air from the system before adding the new one to prevent engine damage, according to the Facebook video. 
• Check with your dealer: If you are unsure which coolant your car uses, contact a BMW dealer and provide your Vehicle Identification Number (VIN) to get the correct specification. 

Does BMW need special coolant?

Yes, BMWs require a special coolant formulated to be nitrite and phosphate-free to prevent corrosion in the aluminum engine components. Using the wrong coolant can damage the water pump, seals, and radiator. Genuine BMW coolant should be mixed with distilled water, typically a 50/50 ratio, before being added to the system.
 
This video explains how to add coolant to a BMW E90/E91/E92/E93 325i/328i/330i: 1mAuto Repair GuysYouTube · Jul 9, 2024
Why BMW coolant is special

• Protects aluminum components: BMW engines are built with aluminum parts, and the specific coolant is designed to prevent corrosion and buildup. 
• Nitrite and phosphate-free: Many common coolants contain nitrites and phosphates, which can cause damage to a BMW’s cooling system. 
• Lifetime coolant: BMW’s “lifetime” coolant is formulated for durability and long-term use, although it still needs to be topped off or changed as recommended by the owner’s manual. 

What to use and how to mix it

• Genuine BMW coolant: The first and safest recommendation is to use genuine BMW coolant. 
• Approved aftermarket coolant: If not using the genuine product, choose a compatible coolant like Pentofrost Blue (which meets the G48 standard) or a modern HT12 green coolant for newer models, but always check compatibility with your specific vehicle. 
• Mix with distilled water: Never add straight coolant to your car. You must mix it with distilled water to achieve the correct ratio for optimal performance. 
• 50/50 mixture: A 50/50 mix is recommended for most applications to balance freeze protection and heat dissipation. 

You can watch this video for a simple guide on BMW lifetime coolants: 1mNoBrainer TalkYouTube · Mar 20, 2022

Can I use other coolants in a BMW?

No, it is not recommended to use other coolants in a BMW because their systems are specifically engineered for the manufacturer’s proprietary formulas, which are designed to prevent corrosion of aluminum components and avoid damage to seals and hoses. Using the wrong coolant can lead to corrosion, gelling, scale buildup, and premature failure of cooling system components like water pumps and radiators. 
Why you should use genuine BMW coolant

• Specific formulation: BMW coolant is formulated to work with the specific materials in their engines to prevent corrosion, especially to aluminum. 
• Corrosion and damage: Using incompatible coolants can cause corrosion, which can lead to premature failure of the water pump, radiator, and other parts. 
• Hose and seal issues: Other coolants can cause hoses to deteriorate and seals to harden, leading to leaks and pressure loss. 
• Mixing is dangerous: Do not mix different types of coolant, as the different chemical inhibitors can react negatively, causing gelling and plugging of the cooling system. 
• Different colors, different types: Even within BMW’s own products, different colors (blue, green, etc.) are for different engine types and water pump materials, so you must use the correct one for your specific model. 

Alternatives to consider

• Emergency use: In an emergency, Pentosin NF antifreeze is sometimes cited as a compatible alternative, but it is best to replace it with the correct BMW coolant as soon as possible. 
• Third-party equivalents: Some forums suggest that specific NAP-free (nitrate, amine, and phosphate-free) coolants from brands like Zerex, Castrol, or Pentosin may be compatible, but you should always double-check for NAP-free certification and compatibility with your specific BMW engine before use. 
• Always use distilled water: If you need to top off or a mix a new batch, only use distilled water, as tap water contains minerals that can build up in the system.