Octane Supreme Fuel Additive

Give classic engines the leaded-fuel protection they were designed around — with Octane Supreme. This is the genuine Tetraethyl Lead (TEL) formulation (not a “lead replacement”), made to help protect valve seats, reduce knock, and bring back the smoother running you expect from older motors. Ideal for vintage cars, motorcycles, competition engines and stationary engines originally set up for leaded petrol.

Not suitable for engines fitted with oxygen sensors and catalytic converters.

Price range: $35.00 through $175.00

Real leaded-fuel performance — brought back for classic engines

Unleaded petrol might be the norm now, but many older engines were engineered with leaded fuel in mind. Octane Supreme is Australia’s genuine Tetraethyl Lead (TEL) fuel additive — the original style of additive that helped older motors live longer, run cleaner, and resist detonation.

If your vehicle or engine was built to run on leaded petrol, Octane Supreme is formulated to help recreate that “real leaded” behaviour in today’s unleaded fuel. It’s suited to classic cars, vintage motorcycles, race applications and stationary engines where TEL is appropriate, helping deliver smoother running, better protection where it matters, and more confidence under load.

Important: Do not use in vehicles fitted with catalytic converters or exhaust/oxygen sensors.

Why many classic engines struggle on modern unleaded

Modern fuels weren’t designed for older valve-train materials and combustion characteristics. Over time, running without TEL can contribute to issues such as valve seat wear, spark knock in higher-compression engines, and a general drop in crispness and drivability. Unleaded fuel can also degrade in storage, leading to harder starts and inconsistent running.

What Octane Supreme helps you achieve

By reintroducing genuine TEL characteristics to unleaded fuel, Octane Supreme is intended to support:

  • Valve seat protection and lubrication where older engines need it most.
  • Improved resistance to knock and pre-ignition, particularly in engines that are more knock-sensitive.
  • Cleaner, more reliable ignition behaviour to help reduce plug fouling and rough running.
  • Better fuel stability during storage, helping fuel stay usable for longer.

The result is a more period-correct running feel — the kind of smoothness, response and sound many classic owners remember.

Key benefits

  • Turns unleaded into a more “true leaded” style fuel experience (for suitable engines).
  • Helps protect valve seats and reduce long-term wear.
  • Octane support — typically around 1 to 5 points depending on dosage and base fuel.
  • Helps reduce knock and improve drivability in knock-prone engines.
  • Helps keep spark plugs cleaner for more reliable hot and cold starting.
  • Acts as a fuel stabiliser to support stored fuel.

Not for engines with catalytic converters or oxygen sensors.

Dosage Guide (per 10L of fuel)

  • Normal use: Add 50 mL per 10L of fuel. Typical octane increase is +1 to +2 points. One bottle treats 100–200 litres.
  • Performance: Add 75–100 mL per 10L of fuel. Typical octane increase is +3 to +4 points. One bottle treats 50–66 litres.
  • Race use: Add 125 mL per 10L of fuel. Octane increase is up to +5 points. One bottle treats 40 litres.
Octane Supreme Fuel Additive