Bilt Hamber Gas-Mac Fuel Tank Corrosion Inhibitor

Gas-Mac is a fuel additive from Bilt Hamber that protects the inside of your fuel tank against rust and corrosion, both above and below the fuel level. It works through vapor-phase inhibitors: molecules that spread through the air inside the tank and reach metal that never touches the liquid directly. That makes Gas-Mac suitable for hollow sections and awkward corners in the tank structure. Beyond corrosion protection, Gas-Mac stabilizes the fuel during long-term storage, which matters for vehicles you park up for months. The additive burns safely in any petrol or diesel combustion engine. You apply it with the supplied injection lance, straight into the filler neck, for targeted protection without spilling.

What's inside

1 bottle of 500 ml Bilt Hamber Gas-Mac fuel additive including a straight fill tube for precise dosing into the tank.

Why this product

• Vapor-phase corrosion protection: the inhibitors spread through the air in the tank and protect metal without direct liquid contact

• Works on petrol and diesel: one additive for either engine type, no separate variants needed

• Stabilizes fuel: prevents breakdown and gumming during long-term vehicle storage

• Burns safely: no changes needed to your engine, fuel system or filters

• Precise dosing: 2 seconds of spray per 10 litres of tank capacity via the supplied injection lance

How to use

1. Remove the standard spray nozzle from the can (Pull straight off and keep the opening away from your face)

2. Click the supplied injection lance onto the can (Hold a cloth over the discharge tube before spraying, this prevents splashing)

3. Insert the lance into the fuel tank filler neck (Spray 2 seconds per 10 litres of tank capacity, moving the lance along the tank wall)

4. Repeat Gas-Mac after every large refuel (This keeps the vapor-phase protection continuously active inside the tank)

Pair Gas-Mac with the Bilt Hamber Ferrosol Penetrating Oil for complete rust protection on metal components.