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Lubricating oil compositions

  • US 7,018,958 B2
  • Filed: 10/22/2002
  • Issued: 03/28/2006
  • Est. Priority Date: 10/22/2002
  • Status: Expired due to Term
First Claim
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1. A method of operating a heavy duty diesel engine equipped with an aftertreatment device containing an oxidation and/or reduction catalyst, which method comprises lubricating said engine with a lubricating oil composition having a TBN of at least about 8, said composition comprising:

  • (a) a major amount of oil of lubricating viscosity;

    (b) an amount of one or more dihydrocarbyl dithiophosphate metal salt introducing into said lubricating oil composition no more than 0.06 wt. % of phosphorus;

    (c) at least 1.2 wt. % of hindered phenol antioxidant;

    (d) boron, and/or a boron-containing compound or compounds in an amount providing said lubricating oil composition with at least 200 ppm by weight of boron; and

    (e) a minor amount of detergent.

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