Internally rusted petrol tanks are not only a problem of classic motorcycles and cars. Unleaded petrol is aggressive and corrodes the tank from the inside.

The problem appeared with the disappearance of leaded gasoline

wema tankmanufaktur: rostiger tank

In 1988 environmental reasons lead to the replacement of leaded fuel with MTBE (methyl tertiary-butyl ether). Unfortunately the new environmentally friendly fuel caused new problems in fuel tanks.

Because MTBE is hygroscopic*, water is now accumulated in petrol tanks, causing slow corrosion. (* The ability to retain moisture from the atmosphere)

Since the late 90s MTBE was replaced by even cheaper chemicals like methanol or ethanol. These alcohols however, absorb even more water and that leads to even faster corrosion.


Other causes of rust

Clogged overflow pipe  
• Vehicles left standing for long periods


Rust particles cause serious damage

The effects are:

• Blocked carburettor jets
Low-pressure petrol valve malfunction
• impaired function of the float needle valves