Millers Classic Mini Oil 20W50

20W-50 oil for classic Mini engines that share oil with the gearbox

Millers Classic Mini Oil 20W50 is a mineral SAE 20W-50 multigrade for engines in which the engine and the gearbox use the same oil, as in the original Mini.

It combines gearbox-oil additives for smoother changes with a full ZDDP (zinc/phosphorus) level, and comes in 1 L, 5 L, 20 L and 60 L.

Key properties

• Grade: SAE 20W-50 multigrade, mineral, moderate detergent level
• Listed: API SF and GL-4
• Viscosity: 147 cSt at 40 °C, 16.7 cSt at 100 °C, viscosity index 122
• Density 0.890, pour point below -15 °C, flash point above 200 °C
• Cold-crank viscosity 9,500 cP max, TBN 10.7, ZDDP 1391
• Packs: 1 L, 5 L, 20 L and 60 L

Choosing the right oil

The original Mini is the clear use case. Its gearbox sits in the sump and shares oil with the engine, so a plain engine oil can wear gears and make gear changes feel notchy. This oil is formulated for exactly that situation, and Millers Oils credits it with improved shift quality and longer life for the idler gears in transverse Mini engines.

It can also be used in other gearbox applications that call for an engine oil, and in some classic motorcycles, preferably those with a non-roller-bearing big end where the clutch runs in the engine oil.

Do not use it where the clutch or gearbox maker asks for a different grade. If your engine has a separate gearbox oil supply, an ordinary classic 20W-50 engine oil may be the simpler choice.