What Kind of Coolant a 2018 Audi A5 Uses

A 2018 Audi A5 is designed to use a pink or purple, phosphate-free, silicate-free, OAT-based coolant that meets Volkswagen/Audi G13 (TL-VW 774 J) or the newer G12++/G12evo specifications—never generic “green” or universal coolant, and never mixed with unknown types.

Understanding the Correct Coolant Specification

The question of which coolant belongs in a 2018 Audi A5 is more than a matter of color; it involves meeting strict chemical and performance standards set by Volkswagen Group. Using the wrong coolant can damage the engine, radiator, water pump and heater core, and can even void warranty coverage or complicate future repairs. For this model year and platform, Audi relies on long-life, organic-acid-technology (OAT) coolants specifically formulated for aluminum-heavy modern engines and tight cooling passages.

Official Audi/VW Coolant Types for the 2018 A5

The 2018 Audi A5 belongs to the MLB Evo platform generation, which uses a family of extended-life coolants defined by Volkswagen/Audi’s internal “G” codes. While color is a helpful visual cue, the specification printed on the bottle is what truly matters.

The following list outlines the relevant coolant specs Audi approves for this vehicle.

• G13 (TL-VW 774 J) – The primary and most commonly referenced specification for a 2018 Audi A5. This is typically pink to light purple. It is an OAT coolant, phosphate- and silicate-free, designed for extended life and compatibility with aluminum components.
• G12++ / G12 Plus Plus (TL-VW 774 G) – An earlier extended-life OAT coolant that is usually pink or violet. Often still compatible and used as a service-fill when G13 is unavailable, provided it explicitly states compliance with the correct VW/Audi spec.
• G12evo (TL-VW 774 L) – A newer-generation coolant that supersedes some older specs in current parts catalogs. It is also a pink/violet OAT coolant and is typically backward-compatible, but always verify compatibility with your VIN at a dealer.

In practice, most Audi dealers today will fill or top off a 2018 A5 with a genuine VW/Audi G13 or its direct successor (such as G12evo) that is confirmed as backward-compatible, ensuring the car’s cooling system retains its designed corrosion and thermal protection.

Why Not Just Use “Universal” Green Coolant?

Many aftermarket coolants marketed as “universal” or “mixes with any color” are not tailored to German manufacturer OAT formulations and may lack the specific inhibitors Audi requires. The 2018 A5’s turbocharged engines and aluminum-intensive construction make coolant chemistry especially important.

Chemistry Differences That Matter

OAT-based coolants like G13 and G12evo are engineered for long change intervals, stable pH, and minimal deposit formation in narrow passages and on sensitive surfaces such as turbocharger housings and aluminum cylinder heads. Classic green IAT (inorganic additive technology) coolants rely heavily on silicates and phosphates, which can cause abrasive deposits, gel formation, and early water-pump seal wear in modern European systems.

How to Identify the Correct Coolant for Your A5

Drivers often rely on color alone, but Audi and VW repeatedly emphasize that specification is the only reliable guide. With aging vehicles and mixed service histories, visual inspection is a starting point, not a guarantee.

Checking What’s Already in the Car

Before adding coolant, it is vital to know what your cooling system currently contains. Mixing incompatible chemistries is one of the fastest ways to ruin coolant performance.

The following steps outline how owners can identify or confirm the existing coolant type in a 2018 Audi A5.

1. Inspect the expansion tank color: When the engine is cold, look at the translucent expansion tank. Factory fill is usually pink or violet. Brown, murky, or mixed colors may indicate contamination or prior use of incorrect coolant.
2. Check the owner’s manual: Audi typically lists the specification (e.g., G13 or “TL-VW 774 J”) in the cooling system or fluids section. If the specific G-code is not spelled out, it will often refer you to “genuine Audi coolant” which aligns with those specs.
3. Look for labels under the hood: Some cars have a coolant type or part-number label near the expansion tank or radiator support indicating G13 or a related spec.
4. Consult a dealer with your VIN: A dealership parts department can look up the correct current-service coolant based on your VIN and confirm whether they use G13 or a superseding product like G12evo.
5. Review service records: Prior work invoices may list the coolant used (e.g., “G13 Coolant / VW TL-VW 774 J”). If a non-OEM shop has used a generic coolant, a complete flush is recommended.

By confirming the existing coolant type, you avoid harmful mixing and ensure that any top-off or replacement maintains the integrity Audi engineered into the cooling system.

Mixing Coolants: What’s Allowed and What Is Not

Even among Audi-approved coolants, mixing is not always ideal; between incompatible types, it can be disastrous. Understanding what can and cannot be combined helps owners make safer decisions when topping off away from a dealer.

Compatibility Rules

The following list summarizes key guidelines on coolant mixing for a 2018 Audi A5.

• Do not mix VW/Audi OAT coolant with generic green IAT coolant: This can cause sludge, reduced corrosion protection, and overheating issues. If you suspect mixing occurred, a full system flush is strongly advised.
• Do not rely on “universal” coolant claims: Unless the bottle explicitly says it meets VW TL-VW 774 specifications (G13, G12++, G12evo), treat it as incompatible for an Audi A5.
• G13 and G12evo are typically backward-compatible with earlier VW/Audi OAT specs, but the best practice is to stick with a single type once the system is filled.
• If coolant type is unknown, flush before refilling: Mixing unknown fluids is risky; a professional flush and refill with a known, correct coolant is the safest choice.
• When in doubt, add only distilled water for a temporary top-off: If you are low in an emergency and cannot confirm the coolant spec, adding a small amount of distilled water is safer than adding an unknown coolant. Then, have the system checked promptly.

Following these compatibility principles helps maintain proper heat transfer, consistent pH, and corrosion protection, all of which are essential for the long-term health of a turbocharged Audi engine.

Concentration, Dilution, and Climate Considerations

Beyond specification, coolant must be mixed with water at the proper ratio to protect against both freezing and overheating. For most climates, Audi and VW target a 50/50 mix by volume of concentrate and distilled water.

Recommended Coolant Mixtures

The following points describe how to approach coolant concentration for a 2018 Audi A5 in different conditions.

• Standard mix: 50% coolant, 50% distilled water – This is generally recommended for most temperate climates, delivering freeze protection down to roughly -35 °C (-31 °F) and robust boiling-point elevation under pressure.
• Colder climates: up to ~60% coolant, 40% water – In extremely cold regions, a slightly higher coolant concentration may be used, but going above ~60% begins to reduce heat-transfer efficiency and is not recommended.
• Never use 100% coolant concentrate: Pure coolant does not conduct heat as effectively and may actually increase operating temperatures, while also altering corrosion-inhibitor behavior.
• Always use distilled or demineralized water for mixing: Tap water introduces minerals that can contribute to scale, deposits, and potential corrosion inside the engine and radiator.
• Pre-mixed OEM coolant: Many Audi/VW bottles are sold pre-mixed at 50/50, which simplifies top-ups and eliminates mixing errors.

Adhering to the correct mixture ensures that the 2018 A5’s cooling system functions efficiently across seasons, minimizes scale buildup, and provides stable protection for aluminum components.

Service Intervals and When to Replace Coolant

While Audi’s extended-life coolants are designed to last for many years, they are not lifetime fluids. Over time, additives deplete and the fluid can become contaminated, especially if the cooling system has been opened for repairs.

Typical Change Timing

Audi’s official maintenance schedules can vary by market and engine variant, and some documentation refers to coolant as “lifetime” under ideal conditions. Nonetheless, many independent European specialists and owners adopt more conservative intervals.

The following recommendations reflect current best practice for a 2018 Audi A5.

• Initial interval: Many technicians recommend a complete coolant replacement around 5 years or 100,000–150,000 km (60,000–90,000 miles), whichever comes first, especially once the vehicle is out of warranty.
• Subsequent intervals: Replacing coolant every 4–5 years thereafter is common to maintain corrosion protection and avoid buildup.
• After major cooling-system work: Any time a radiator, water pump, heater core, or major hose assembly is replaced, a full drain, flush (if contamination is suspected), and refill with fresh OEM-spec coolant is recommended.
• If coolant looks discolored or contaminated: Brown, milky, or heavily cloudy coolant, or evidence of oil contamination, warrants immediate diagnostic investigation and a complete fluid replacement.
• Monitor coolant level regularly: Slow coolant loss over time may indicate minor leaks; topping off is acceptable as long as the correct coolant is used and the leak source is addressed.

Managing coolant proactively rather than reactively helps prevent overheating, internal corrosion, and expensive damage to the head gasket, turbocharger, and other cooling-related components.

Practical Advice for Owners

For everyday owners, coolant care often feels intimidating due to the chemical complexity and warnings against mixing. Yet a few practical steps make it straightforward to keep a 2018 Audi A5 within factory specifications.

What to Do in Real-World Situations

The following points offer concrete guidance for typical scenarios an A5 owner may face.

• If the low-coolant light comes on: Park safely, let the engine cool completely, and inspect the expansion tank. If you have OEM G13/G12evo on hand, you can top off to the “MAX” mark. If you are unsure of the existing coolant type, use only a small amount of distilled water and seek service soon.
• Buying coolant yourself: Look for bottles labeled “VW/Audi G13” or “meets TL-VW 774 J” or the approved G12evo spec. Avoid generic products that do not list a specific VW standard.
• Using independent shops: Confirm that they use VW/Audi-approved coolant. Ask them to list the exact spec on the invoice to document compatibility.
• Storing coolant: Keep any leftover OEM coolant in its original container, tightly sealed, away from children and pets. Do not mix brands or types in the same bottle.
• Disposing of old coolant: Used coolant is toxic and must be disposed of at a recycling center or service facility that accepts hazardous fluids, not poured down drains or onto the ground.

These simple practices help owners stay aligned with Audi’s engineering intentions, avoid costly mistakes, and maintain reliable temperature control under a wide range of driving conditions.

Summary

A 2018 Audi A5 is engineered to use a VW/Audi-approved, pink or violet OAT coolant—most commonly G13 (spec TL-VW 774 J), or a compatible successor such as G12evo—never generic green or “universal” coolant. Owners should verify the specification on the bottle, avoid mixing unknown types, maintain a 50/50 coolant-to-distilled-water ratio in most climates, and replace the fluid at sensible intervals or whenever contamination is suspected. By following Audi’s coolant standards and best practices, A5 drivers protect their engines, turbos, and cooling systems from premature wear and expensive repair.

Does Audi need special coolant?

But unlike generic vehicles, Audi coolant is different. It’s specially formulated to work with Audi’s aluminum engine components and precision-engineered cooling systems.

What color coolant for Audi?

Audi coolant is typically purple or pink but can also be turquoise. The specific color depends on the generation and type of coolant, such as the older G12/G12+ (pink) or the newer G13 (purple/lilac) and G12 Evo (often referred to as violet or pink). It is crucial to use the correct coolant for your Audi model, as mixing different types can damage the cooling system.
 
You can watch this video to learn about different types of Audi coolants and what can be mixed together: 57sFCP EuroYouTube · Jul 23, 2024
Common Audi coolant colors

• Purple: Newer models often use G13 coolant, which is purple or lilac. Some manufacturers also offer a purple G12 Evo coolant. 
• Pink: Older models may use G12 or G12+ coolant, which is pink. 
• Turquoise: Some European manufacturers, including Audi, also use a turquoise coolant, which is a NAP-free (Nitrite, Arsenic, and Phosphorus free) formula. 

Why using the correct color is important

• Compatibility: Each color is designed for specific engine and cooling system requirements. Using the wrong type can cause damage or malfunctions. 
• Avoid corrosion: Correctly formulated coolant helps prevent corrosion and maintains the efficiency of high-performance engines. 
• Mixing danger: Mixing different types of coolant is strongly discouraged. It can compromise the integrity of the cooling system and lead to serious problems. If you are unsure which coolant to use, it is best to perform a full flush and fill with the correct specification. 

What type of coolant for Audi A5?

The correct coolant for an Audi A5 is Audi/VW G13, which is a lilac or pink-colored, long-life coolant. However, older models may have used other specifications like G12 or G12++, so it is crucial to check your vehicle’s owner’s manual for the exact requirement. Always use the specified Audi/VW coolant or a compatible OEM-approved antifreeze to avoid damage to the cooling system. 
Key coolant types for Audi A5

• G13: The most current specification, typically lilac or pink. It is a long-life coolant designed for newer models and is compatible with aluminum parts. 
• G12++: Another compatible specification for some models, often with a purple or reddish-purple color. 
• G12: An older specification that may be used in earlier models. 

Important considerations

• Check your owner’s manual: The most reliable way to determine the correct coolant is to consult your vehicle’s owner’s manual. 
• Avoid generic coolants: Do not use generic, store-bought coolants that are not specifically approved for Audi or VW vehicles, as they may not meet the specific performance requirements of the cooling system. 
• Color is not a reliable indicator: Do not rely solely on color to determine the correct coolant, as different manufacturers use different colors for their products, even if they meet the same specifications. 

Which coolant for Audi A5 2018?

2018-2020 Audi A5 Sportback. Notes: Coolant / Antifreeze – Audi/VW G13 (Lilac) (5 Liter) — Compatible with all colors of Audi/VW coolant / antifreeze.; Concentrate. For distilled water, see part # 55 7864 010.