| abstract |
Disclosed are a lubricating oil composition for a diesel engine having a decreased ash content which can exert excellent engine detergency and deposit-resistant properties without impairing the performance of an exhaust gas post-treatment device such as a particulate exhaust matter trap or an oxidation catalyst, and a method for the lubrication of the diesel engine which comprises using this lubricating oil composition. The present invention provides a lubricating oil composition for a diesel engine which is obtained by blending a lubricant base oil with (A) 5 to 20% by weight of a boron-containing ashless dispersant and (B) 0.01 to 30% by weight of metal-type detergents having a total base number of 0 to 200 mg KOH/g, based on the total weight of the composition, a sulfated ash content in the composition being 1.0% by weight or less, a boron content being 0.1% by weight or more, and a method for the lubrication of a diesel engine which comprises using the above-mentioned lubricating oil composition in a diesel engine provided with an exhaust gas post-treatment device. |