| abstract |
To improve the performance of a heavy duty diesel (HDD) engine with an exhaust gas recirculation system ( EGR ). An engine comprising an EGR system in which an intake air and / or exhaust gas recirculation stream is cooled below its dew point for a time of at least 10% of the operating time of the HDD engine. And a lubricating oil composition comprising a small amount of one or more polymer polymers including (i), (ii) and / or (iii) below: The engine: (I) a copolymer of hydrogenated poly (monovinyl aromatic hydrocarbon) and poly (conjugated diene), wherein the hydrogenated poly (monovinyl aromatic hydrocarbon) segment comprises 20%; (Ii) specific olefin copolymers; and / or (iii) acrylate or alkyl acrylate copolymer derivatives having dispersing groups. [Selection] Figure 1 |