FAQ

Viscosity is a measure of a fluid’s resistance to flow. A fluid with low viscosity flows easily and is often called “thin.” Water is an example of a fluid with a relatively low viscosity. A fluid with high viscosity is often described as “thick.” Maple syrup is an example of a fluid with a relatively high viscosity.

Synthetic products are produced by chemical reactions in which pressure, temperature and the ratio of component elements are carefully controlled. This results in a pure compound with maximized lubricating properties, which can lead to enhanced energy efficiency, improved equipment protection, more reliable equipment performance and extended oil service life.

Greases are manufactured by combining three essential components: base oil, thickener and additives. Base oils are the liquid portion of any grease and may be mineral, synthetic, or any fluid that contains lubricating properties. Thickeners may be any material that, in combination with the base oil, produces the solid to semi-fluid structure. As in lubricating oil additives, grease additives and modifiers impart special properties or modify existing ones.

Mixing different types of greases can sometimes lead to incompatibility problems. Grease incompatibility results from chemical interactions between the thickener or additive systems of the dissimilar greases. In some cases, grease incompatibility can lead to equipment failure or damage of the lubricated components. Mixtures of incompatible greases will exhibit either excessive hardening or softening relative to the consistency of the individual pure greases. The hardening or softening tendencies of the mixture will generally become more pronounced as the operating temperature increases or as the rate of shearing on the grease mixture increases. Incompatible greases may also exhibit excessive oil separation or “bleeding” tendencies at higher temperatures.

Mixing different types of greases can sometimes lead to incompatibility problems. Grease incompatibility results from chemical interactions between the thickener or additive systems of the dissimilar greases. In some cases, grease incompatibility can lead to equipment failure or damage of the lubricated components.Mixtures of incompatible greases will exhibit either excessive hardening or softening relative to the consistency of the individual pure greases. The hardening or softening tendencies of the mixture will generally become more pronounced as the operating temperature increases or as the rate of shearing on the grease mixture increases. Incompatible greases may also exhibit excessive oil separation or “bleeding” tendencies at higher temperatures.

Mixing different greases, even those with similar thickener types, can sometimes lead to ineffective lubrication resulting in damage of the lubricated components. If not spotted soon enough this may lead to equipment failure. These situations occur due to chemical or structural interaction between the thickener or additive systems of the different greases which would be classified as “incompatible.”

Symptoms of incompatibility come in various forms. Most frequently grease mixtures will exhibit a change in consistency relative to that of the individual pure greases. This tendency will be more pronounced as the operating temperature or the rate of shearing of the grease mixture increases. Incompatible greases may also exhibit abnormal oil separation or “bleeding” at higher temperatures. If greases that are incompatible are mixed in application it could lead to grease or oil leakage, premature aging or insufficient oil bleed in the contacting zones. Although less probable but not unknown, the greases’ performance additives may act antagonistically, adversely affecting the lubrication performance such as protection against friction, wear, rust or corrosion.

If you have ever opened a grease container and found a puddle of free oil, you almost certainly may have wondered whether the grease is still fit for use. The phenomenon described is called static oil bleed. Some in-depth review of grease fundamentals is needed to comprehend it is inherent to greases.

There are several reasons to lubricate plain bearings with grease:

  • As a result of the lower end leakage, the amount of lubricant required for the bearing is lower.
  • When a grease-lubricated bearing is stopped for any period of time – with the flow of lubricant shut off – the high apparent viscosity of the static grease reduces end leakage sufficiently so the grease usually does not completely drain or squeeze out.
  • Some grease remains on the bearing surfaces so that a fluid film can be established almost immediately upon startup. As a result, torque and wear during the starting phase may be greatly reduced.
  • During shutdown periods, retained grease also acts as a seal to prevent the entry of dirt, dust, water, water vapor and other environmental contaminants and, thus, protects the bearing surfaces against rust and corrosion.

The dropping point is the temperature when the first drop of oil falls from the test cup and reaches the bottom of the test tube under ASTM D 2265. It’s a good indicator of grease type in terms of thickener types, such as organic, inorganic or soap/complex soap. As the test method indicates, the dropping point alone has only limited significance with respect to service performance. The operating temperature of a grease product depends on components, base oil, thickener, additives, etc. High-temperature greases are often synthetic-based inorganic or soap/complex soap greases, such as Primus greases.

When using Primus Antifreeze with a 50/50 antifreeze/water mix, we recommend adding 1 ounce of Primus Antifreeze per quart of cooling system capacity. For straight water (racing) or higher water ratio applications, we recommend adding 2 ounces of Primus Antifreeze per quart of cooling system capacity.

When used with antifreeze, Primus Antifreeze should be added once a year or every 30,000 miles (48,280 km), whichever comes first, in order to maintain proper performance. When using Primus Antifreeze in a cooling system running straight water, Primus Antifreeze should be added once a year or every 15,000 miles (24,140 km), whichever comes first.

Yes. Primus Antifreeze may be used in diesel engines for improved heat transfer as well as reduced cavitation.

It forms non-combustible gums that form deposits in fuel systems / combustion chambers, which decreases engine performance / fuel economy and increases emissions.

Yes. Mileage and/or age is not a factor when used in a mechanically sound engine. In high-mileage applications, we do recommend running a minimum of two short 3,000 mile (5,000 km) intervals before extending the oil drain intervals. This will enable Primus Oil’s high solvency to remove existing deposits gradually; if excessive, such deposits can restrict oil flow, as well as reduce the oil service life significantly.

Yes. Primus Oil currently offers many viscosity grades of API-licensed motor oils1. To allow for proper break-in of the engine, Primus Oil recommends waiting until the manufacturer’s first scheduled oil change or a minimum of 2,000 miles (3218 km) in new gasoline engines. Allow a minimum of 6,000 miles (9656 km) before using Primus Oil in diesel engines.

Primus Oil suggests adhering to manufacturer’s recommended oil change intervals for vehicles under warranty using Primus Oil API-licensed SAE motor oils. With Primus oils, drain intervals may be extended to 15,000 miles (20,000 km) or one year, whichever occurs first in street-driven, mechanically-sound vehicles. 

Primus Oil suggests adhering to manufacturer’s recommended oil change intervals for vehicles under warranty. Vehicles no longer under warranty using Primus Oil, that hold 10-quarts of oil or more, can extend oil change intervals up to 15,000 miles (24,140 km) or one year, whichever occurs first in street-driven, mechanically-sound vehicles. For smaller capacity engines, oil change intervals should be every 12,000 miles (19,312 km) or one year.

Properly formulated synthetic oils will generally not cause an engine oil leak. Synthetic oils possess a higher degree of natural solvency, which can clean and remove deposits left by previous oils. The removal of extensive oil deposits can expose marginal or damaged oil seals, which may then leak. If an engine currently has excessive oil consumption (i.e. greater than 1 quart / 1,000 miles) the recommended course of action is to solve the oil consumption problem before switching to a synthetic.

Primus Oil 10W-40 or 20W-50 motor oil may be used in the primary tank. For transmissions, Primus Oil recommends Primus 20W-50 or Primus 75W-90. NOTE: DO NOT use Primus lubricants in the primary or in any other component containing a wet clutch.

For all Harley Davidson and other air-cooled V-twin motorcycles, we recommend Primus Oil 20W-50. If the owner’s manual recommends a 10W-40 or 15W-40, Primus Oil 10W-40 is the best option.

Primus Oil suggests adhering to manufacturer’s recommended oil change intervals for vehicles under warranty. Vehicles that are no longer under warranty can frequently double or triple the number of miles between oil changes depending on the vehicle, its condition, the way it’s used (excessive idling), and the oil filter that is used.