Risks of Mixing Oils in Diesel Generators

During use or maintenance of diesel generators, some users may mix new and used engine oil, or blend oils of different brands or specifications for convenience or as a temporary emergency measure. Such practices carry significant risks and can easily cause irreversible damage to diesel generator sets.

Mixing New and Used Engine Oil Accelerates Performance Degradation

After prolonged use, used engine oil contains a large amount of oxidized substances, carbon deposits, and impurities. If mixed with new oil, these contaminants rapidly catalyze the oxidation process of the new oil, leading to the premature decline of its core performance indicators such as cleaning and anti-wear properties. This effectively shortens the maintenance cycle and increases upkeep costs.

Mixing Oils of Different Brands or Specifications Creates Hidden Dangers Due to Chemical Reactions

Even if labeled with the same viscosity grade, engine oils of diesel generators from different brands or series may have significant differences in their base oil refining processes and the chemical composition of their additive packages. Blindly mixing them can lead to the following issues:

1. Chemical reactions between additives may generate flocculants or sediment, causing the oil to become cloudy, clogging filters, and impairing normal lubrication circulation.

2. Additives from different formulations may interfere with each other, significantly reducing the effectiveness of cleaning, anti-oxidation, anti-wear, and other functions.

3. This compromises the stable oil film strength, causing key moving parts (such as pistons, cylinder walls, bearings) to operate under conditions of dry friction or inadequate lubrication. In severe cases, this can lead to major mechanical failures like cylinder scoring or bearing damage.

4. Mixed oil has reduced stability and is more prone to oxidation, forming gums and sludge. These substances can adhere to the engine internals, affecting heat dissipation, clogging oil passages, and creating a vicious cycle.

5. Mixed oil may alter sealing performance or cause oil to participate abnormally in combustion, resulting in black or blue smoke from the diesel generator exhaust pipe.

Mixing Gasoline and Diesel Engine Oil: Incompatible Formulations Lead to Frequent Failures

Gasoline engine oil and diesel engine oil have fundamentally different base oils and additive formulations. Diesel engines operate under higher pressure, placing stricter demands on the oil's shear stability, detergency/dispersancy, and base number (TBN). If gasoline engine oil is mistakenly used in a diesel generator set, it can likely lead to the following problems:

• Inadequate oil film strength under high temperature and pressure, leading to increased wear.

• Mismatched cooling and cleaning capabilities, easily causing abnormal engine temperatures.

• Mismatched viscosity characteristics increase the risk of wear during startup.

To ensure the reliable operation and long service life of your diesel generator set, it is strongly recommended that you:

• Strictly adhere to the oil specifications recommended by the equipment manufacturer (including API grade, SAE viscosity grade, etc.).

• Aim for a complete oil change during generator maintenance, and replace the oil filter simultaneously.

• Consistently use products from the same brand and series to ensure compatibility of the additive system and sustained stable performance.

• If oil must be added in an extreme emergency, prioritize using a product of the same brand, same specification, and same viscosity grade as a temporary supplement, and schedule a complete oil change as soon as possible.

Guangxi Dingbo Generator Set Manufacturing Co., Ltd. specializes in the production of: Diesel Generator Sets: 0.5kVA~3750kVA,Gasoline Generators: 1kW~50kW, Natural Gas Generators: 0.5kVA~3750kVA, Welding Generators: 5A~600A, LPG/Gasoline/Natural Gas Dual Fuel Generators: 8kW~50kW, Water Pump Generator Sets: 20kW~1000kW.

Hotline/whatsapp : +86 13878801642