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Millers Oils CRO 10W-40 Competition Running In Oil

by Millers

Millers Oils CRO 10W-40 Competition Running In Oil

Millers Oils CRO 10W-40 is a competition running in oil for test bed running for up to 4 hours. It features an advanced formulation of high quality solvent refined mineral oils fortified with special low volatility components and appropriate additive treatment. This 10w40 viscosity grade mineral oil has been carefully formulated to offer an extremely high protection level to new engine components and speed up the bedding in process.

Ideally suited for test bed running. May also be used for light operational duties up to 500mls/800kms. Developed for modified petrol and diesel engines.


  • Formulated to meet the needs of the professional engine builder
  • Maximises power output by optimising bedding in process
  • Provides full protection of highly stressed components whilst allowing optimum bedding in process for piston rings and bore
  • Additive technology enables full load runs for short bursts
  • The viscometrics selected ensure that even though the additive system performance is strong the pistons can achieve satisfactory boundary lubrication for bedding purposes


  • Suitable for 5 hours test bed running or 500mls/800kms on road
  • Optimum oil temperature 85-115°C
  • Very low leak down [4%] after controlled test bed running
  • 5L