What Coolant a 2017 Audi S3 Uses — and Why It Matters

The 2017 Audi S3 is designed to use VW/Audi–approved “G12”-family, silicate-free, OAT-based coolant that meets Volkswagen TL 774 specifications (such as G12++, G13, or current G12evo), typically supplied as a pink or purple concentrate to be mixed 50/50 with distilled water. Using universal green coolant or non-approved formulas is not recommended and can risk damage to the cooling system.

The Basics: Official Coolant Specification for the 2017 Audi S3

Audi does not specify coolant by generic brand name but by an internal standard and chemical type. Understanding those specifications is key to buying the right product, even if it’s not sold under the Audi logo.

Official VW/Audi Coolant Standard

For a 2017 Audi S3 (8V chassis), the factory-spec engine coolant is based on Volkswagen’s “G12” family of coolants. These are long-life, silicate-free coolants that use Organic Acid Technology (OAT) or hybrid OAT chemistry and meet the VW coolant norm TL 774.

The main compatible VW/Audi coolant types for this model year are:

• G12++ (TL 774-G) – Pink/purple, OAT-based, backward compatible with G12 and G12+
• G13 (TL 774-J) – Purple/violet, glycerin-based hybrid OAT, designed as an evolution of G12++
• G12evo (latest spec, TL 774-L) – Modern replacement sold by Audi today, backward compatible with prior G12/G13 types

All these coolants are designed to be mixed only with each other (within the G12/G13 family), not with generic “green” or older silicated coolants. When buying today, Audi dealers typically supply G13 or the newer G12evo as the official replacement.

Color and Chemistry

While color alone is not a standard, Audi/VW coolants for this era of S3 are typically:

• Pink–purple (G12++ and many G13 blends)
• Purple/violet (G13 and some G12evo)

If your coolant is bright green or blue and the car’s history is unknown, it likely does not conform to the original Audi specification and may warrant a full flush and refill with the correct fluid.

How to Identify the Correct Coolant for a 2017 Audi S3

Because product names and bottles vary by region and over time, it’s safer to match the specification and approval numbers than to shop by color or marketing terms.

1. Look for VW/Audi Approvals on the Label

Most suitable aftermarket coolants will explicitly say they meet a VW or Audi standard. For a 2017 S3, you should look for:

The following criteria will help ensure the aftermarket coolant is acceptable for your S3’s cooling system:

• VW/Audi norm such as “VW TL 774-G”, “VW TL 774-J”, or “VW TL 774-L”
• Wording like “Suitable for use in VW/Audi G12++ / G13 applications”
• Statements like “Silicate-free OAT” or “Hybrid OAT” coolant

If the label does not mention any VW/Audi approval or TL 774 code, it is not a safe assumption that the product is compatible with your S3.

2. OEM Products vs. Aftermarket Equivalents

Drivers can choose between Audi-branded coolant and compatible third-party equivalents; both can be safe if they meet the right standard.

When deciding between dealer coolant and aftermarket alternatives, consider the following options:

• Audi Genuine Coolant – Sold at dealerships and many VAG specialist shops as G13 or G12evo concentrate
• Reputable aftermarket brands – Products from major manufacturers (e.g., Pentosin, Febi/Bilstein, Zerex, etc.) that state VW TL 774-G/J/L or “meets/exceeds G12++/G13”
• Avoid generic “universal” green coolant – Unless it explicitly lists VW TL 774-G/J/L compatibility, do not use it in an Audi S3

Using properly approved aftermarket coolant can be as safe as using the dealer product, provided the container clearly lists the correct VW specification.

Mixing and Dilution: Concentrate vs. Pre-Mix

The coolant in a 2017 Audi S3 is typically supplied as a high-strength concentrate and diluted with water. Getting the mixture right affects both cooling performance and freeze/boil protection.

Recommended Coolant/Water Ratio

Most technical documentation and Audi dealership practice rely on a balanced mix for everyday driving conditions.

For most climates where a 2017 S3 is driven, the ideal mixture follows these general guidelines:

• 50% coolant / 50% distilled water – Common “standard” mix, provides robust freezing and boiling protection
• 60% coolant / 40% water – For very cold regions where deeper freeze protection is needed
• Never exceed ~60% coolant – Too much concentrate can actually reduce heat transfer efficiency

This ratio ensures the antifreeze component works effectively while still allowing enough water content for optimal thermal performance.

Use Distilled or Deionized Water

Tap water may contain minerals that can accumulate in the cooling system and contribute to scaling or corrosion inside the narrow passageways of a turbocharged engine’s cooling circuit.

To minimize mineral buildup and corrosion, take the following precautions when mixing coolant:

• Prefer distilled or deionized water when diluting concentrate
• Avoid hard tap water which can leave deposits over time
• Use premixed coolant (already 50/50) if distilled water is not readily available

Maintaining water purity in the coolant mixture supports long-term reliability of the water pump, radiator, and heater core.

Can You Mix Different Coolants in a 2017 Audi S3?

Mixing coolant types is one of the more common mistakes owners make, especially during emergency top-ups. The S3’s modern aluminum-intensive cooling system is sensitive to chemistry mismatches.

Mixing Within the G12/G13 Family

Audi’s official position is that coolants from the same approved family are mutually compatible. In practical terms, that offers some flexibility.

When topping up or changing coolant, it is generally safe to:

• Mix G12, G12+, G12++, G13, and G12evo together – As long as they all meet VW TL 774 series norms
• Top off G12++ or G13 with newer G12evo – The newest formulation is designed as a backward-compatible replacement
• Stay within one family where possible – Even if technically compatible, avoid creating a “cocktail” of different brands without need

This compatibility means you do not need to panic if a dealer uses newer G12evo in a system originally filled with G13 – they are designed to work together.

Mixing with Non-Approved or “Universal” Coolants

In contrast, mixing genuine G12/G13 coolant with generic “universal” or old-style green coolant can create significant issues over time.

If the wrong coolant has been added, be aware of the following potential consequences:

• Gel or sludge formation when OAT and traditional silicated coolants interact
• Reduced corrosion protection for aluminum components, water pump, and radiator
• Potential overheating due to clogged passages or compromised heat transfer

If you suspect non-approved coolant has been mixed in, a complete flush and refill with the correct Audi-spec coolant is the safest approach.

Changing and Maintaining Coolant in the 2017 Audi S3

While Audi often describes these coolants as “long life,” they are not lifetime fluids. Over time, additive packages degrade, and contamination can occur.

Service Intervals and Checks

Official maintenance schedules can vary slightly by market, but modern VAG practice for these coolants tends to emphasize condition-based checks rather than extremely frequent full changes.

For practical ownership of a 2017 S3, consider these guidelines:

• Inspect coolant level and color at least a few times per year, and before long trips
• Top up only with correct G12/G13-spec coolant, not water alone unless it’s a very small, temporary adjustment
• Plan a full coolant change roughly every 5 years or 60,000–80,000 miles (96,000–130,000 km), or sooner if contamination or unknown history is suspected

Regular visual checks can catch slow leaks or early discoloration before they turn into more serious issues.

Practical Notes for Owners and Shops

Cooling system work on a turbocharged performance car like the S3 is more sensitive than on older, simpler engines, so good practice matters.

Whether you or a professional is servicing the coolant, it’s wise to keep these points in mind:

• Never open the coolant reservoir when the engine is hot – Wait for it to cool fully to avoid burns and pressure release
• Bleed air properly from the system after a full flush to prevent air pockets and hotspots
• Use only clean funnels and containers to avoid introducing dirt or incompatible fluids

Attention to these details can prevent overheating and premature wear of key components like the turbocharger and head gasket.

Summary

The 2017 Audi S3 is engineered to use VW/Audi-approved G12-family coolant—specifically long-life, silicate-free OAT or hybrid OAT antifreeze that meets Volkswagen TL 774 standards (such as G12++, G13, or the newer G12evo). These coolants are typically pink or purple and must be diluted with distilled water, commonly at a 50/50 ratio. While G12, G12+, G12++, G13, and G12evo are mutually compatible within the VW/Audi ecosystem, they should not be mixed with traditional green or non-approved “universal” coolants. For best results and longevity of the S3’s high-performance, aluminum-rich cooling system, use either genuine Audi coolant or a reputable aftermarket product explicitly approved to VW TL 774-G/J/L, and follow sensible inspection and service intervals.