Kroon Oil Classic Gear ZC 90

Mild-EP SAE 90 gear oil for classic Alfa Romeo, Fiat and Lancia gearboxes

Kroon-Oil Classic Gear ZC 90 is a mild EP, mineral SAE 90 gear oil at API GL-3 level. It is specified for manual gearboxes of classic Alfa Romeo, Fiat and Lancia cars that call for an OlioFiat ZC 90 oil.

It is sold in a 1 L tin.

Key properties

• Grade: SAE 90 monograde, API GL-3, Oliofiat ZC 90
• Viscosity: 220 mm²/s at 40 °C, 18.9 mm²/s at 100 °C, viscosity index 95
• Density 0.893 kg/l at 15 °C, flash point (COC) 245 °C, pour point -18 °C
• Acid number 0.75 mg KOH/g
• Compatible with yellow metals such as copper, brass and bronze
• Compatible with classic seals and rubbers

Choosing the right oil

This is a niche but important grade: the mild EP additive level and yellow-metal compatibility are exactly what some older Italian gearboxes were designed for. If your handbook names OlioFiat ZC 90 or asks for GL-3, this is a direct match. If it asks for a stronger GL-4 or GL-5 oil, use the matching Classic Gear product instead; heavier EP additives are not automatically better in a gearbox that was never designed for them.

Lightly to medium loaded manual gearboxes are the stated use. For axles and differentials check the manual separately before deciding on an oil.