Why the Golden Ratio (55:45) Makes PG55 RC the Best Engine Coolant for Performance and Racing

Why the Golden Ratio (55:45) Makes PG55 RC a Game-Changer in Engine Cooling

When it comes to engine coolant, not all formulas are created equal. At Kemitec, our PG55 RC stands apart because of one critical detail: the 55:45 golden ratio of propylene glycol to ultra-purified water. But what makes this specific ratio so special—and why do top racing teams trust it?

What Is the Golden Ratio (55:45)?

The “golden ratio” in PG55 RC refers to a precisely engineered formula of 55% propylene glycol and 45% ultra-purified water. This isn’t just a marketing phrase — it’s the result of motorsport testing and scientific refinement to balance cooling performance, thermal stability, and environmental safety.

Why This Ratio Outperforms 50:50 and OEM Coolants

Superior Thermal Stability

The 55:45 formula is more stable under high-heat, high-RPM conditions. Whether you're pushing hard on the track or sitting in stop-and-go traffic, PG55 RC resists boiling, cavitation, and pressure loss better than a typical 50:50 mix.

Wider Operating Temperature Range

PG55 RC delivers reliable protection from -40°C (-40°F) to 107°C (224.6°F), providing a broader safety margin than conventional coolants.

Prevents Vapor Lock and Scaling

Combined with ultra-purified water, the golden ratio helps reduce vapor lock, mineral scaling, and electrolysis — essential for protecting engines made with aluminum, cast iron, or mixed metals.

Eco-Friendly and Non-Toxic

Even at 55% glycol, PG55 RC is non-toxic and biodegradable. Unlike traditional ethylene glycol coolants, it’s safer for your car, your garage, and the environment.

Proven on the Track, Refined for the Street

This golden ratio was developed through real racing, not just lab simulations. It’s trusted in Japan’s premier motorsport series — including Super GT, D1 Grand Prix, and All Japan Road Race. PG55 RC has earned its reputation under the most extreme conditions.

Two Coolants, One Golden Standard

PG55 RC: Precision for High-Performance and Motorsports

Antifreeze Type: Golden Ratio Prediluted (55:45)

PG55 RC is trusted by Japan’s top racing teams in SUPER GT, SUPER FORMULA, and D1 GRAND PRIX. Engineered for high-performance engines and motorsport use, it delivers unrivaled cooling under extreme heat cycles and RPM loads. Built on the scientifically proven golden ratio, PG55 RC combines:

55% propylene glycol
43.7% high-precision filtered water
1.3% advanced additives

PG55 NR358: Durability for Cast Iron and Diesel Engines

Antifreeze Type: Golden Ratio Prediluted (55:45)

PG55 NR358 is built for heavy-duty environments and older engine designs — especially cast iron and diesel engines. It offers superior heat control, corrosion resistance, and system durability, even under continuous load. PG55 NR358 uses the same golden 55:45 formulation, tailored with a different additive balance:

55% propylene glycol
40% high-precision filtered water
5% rust inhibitors, anti-foaming agents, and additives

Why It Matters for You

Whether you’re tracking your tuned Silvia or maintaining a heavy-duty diesel truck, the 55:45 formula gives you reliability, consistency, and peace of mind. It’s more than a coolant — it’s a performance upgrade backed by real-world racing and engineering excellence.