A lubricant composition for a compression-ignition internal combustion engine comprises: (i) an amine as an ashless fuel additive having a total base number (“TBN”) of from about 275 to about 600 mg KOH/g when tested according to ASTM D2896; and (ii) a detergent selected from metal sulfonates, phenates, salicylates, carboxylates, thiophosphonates, and combinations thereof. The lubricant composition has a TBN of from about 20 to about 130 mg KOH/g when tested according to ASTM D2896. The amine contributes greater than about 30% of the TBN of the lubricant composition. Further, a method of lubricating an internal combustion engine with the lubricant composition comprises the steps of injecting a fuel and the lubricant composition into a cylinder to form a mixture, and combusting the mixture via compression-ignition.