Lubricating Oil Composition for Engine Fuel Efficiency and LSPI
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Solution Overview
Problem
Conventional lubricating oils fail to balance fuel efficiency, Low Speed Pre-Ignition (LSPI) suppression, and detergency, often compromising on viscosity and additive content which leads to issues like wear, seizure, and increased evaporation loss.
Innovation Solution
A lubricating oil composition comprising a mineral or synthetic base oil with specific viscosity ranges, calcium borate-containing metallic detergent, and optional viscosity index improver and molybdenum friction modifier, optimized to maintain high temperature high shear viscosity and reduce evaporation loss.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of energy
If the viscosity of a lubricating oil is reduced to improve fuel efficiency, then fuel efficiency is improved, but lubricating performance under severe conditions deteriorates leading to wear, seizure, and fatigue failure
Solution Approach 1:
The patent applies parameter changes by precisely controlling the kinematic viscosity at 100°C within 3.5 to 5.0 mm²/s and HTHS viscosity at 150°C within 1.7 to 2.3 mPa·s. This optimized viscosity range reduces energy loss while maintaining sufficient lubricating film strength under severe conditions, preventing wear and seizure without compromising fuel efficiency
Solution Approach 2:
The patent uses a composite base oil formulation combining Group II base oil (70-90 mass%) and Group III base oil (10-30 mass%). This composite structure achieves both low viscosity for fuel efficiency and high viscosity index for stable lubricating performance across temperature ranges, resolving the contradiction between reduced viscosity and maintained reliability
2Loss of energy
If a friction reducing agent is incorporated to improve fuel efficiency, then fuel efficiency is improved, but detergency performance deteriorates
Solution Approach 1:
The patent optimizes the calcium content from conventional high levels to a specific range of 800-2000 mass ppm, and controls the molar ratio of boron to calcium within 0.3-2.0. This parameter optimization reduces friction for fuel efficiency while the boron-containing detergent maintains superior detergency by forming protective deposits and preventing sludge accumulation
Solution Approach 2:
The patent introduces boron-containing detergent as an intermediary substance that mediates between friction reduction and detergency requirements. The boron compounds form protective boundary films that reduce friction while simultaneously providing excellent detergent properties, thus resolving the contradiction between friction reduction and detergency maintenance
3Object-affected harmful factors
If calcium detergent is reduced to suppress LSPI, then LSPI suppression is improved, but detergency performance deteriorates
Solution Approach 1:
The patent precisely controls calcium content within 800-2000 mass ppm and boron content within 200-1000 mass ppm, with a molar ratio B/Ca of 0.3-2.0. This optimized parameter combination suppresses LSPI by reducing excessive calcium deposits while the boron-containing detergent compensates for detergency, maintaining clean engine operation through balanced additive chemistry
Solution Approach 2:
The boron-containing detergent acts as an intermediary that enables LSPI suppression at reduced calcium levels while maintaining detergency. The boron compounds provide dual functionality: suppressing pre-ignition through controlled deposit formation and maintaining detergent performance through their ability to solubilize and disperse contaminants
4Loss of energy
If a less viscous base oil is used to improve fuel efficiency, then fuel efficiency is improved, but volatility increases leading to increased oil consumption
Solution Approach 1:
The patent employs a composite base oil system combining Group II base oil (70-90 mass%) and Group III base oil (10-30 mass%). This composite formulation achieves low viscosity at 100°C for fuel efficiency while the high viscosity index of Group III oil maintains adequate viscosity at operating temperatures, reducing volatility and oil consumption through synergistic blending
Data Source
AI summary
A lubricating oil composition for an internal combustion engine, the composition including: a lubricating base oil comprising at least one mineral base oil or at least one synthetic base oil or any combination thereof, the lubricating base oil having a kinematic viscosity at 100° C. of 4.0 to 4.5 mm2/s and a NOACK evaporation loss at 250° C. of no more than 15 mass %; (A) a calcium-containing metallic detergent in an amount of no less than 1000 mass ppm and less than 2000 mass ppm in terms of calcium on the basis of the total mass of the composition; and optionally (C) a viscosity index improver in an amount of less than 1 mass % on the basis of the total mass of the composition.