Oil thinning on gasoline engines
When an over-rich fuel mixture enters the cylinders, or when the engine is rarely or never required to develop its full power, or when the engine is often operated in a cold state (short city trips), resulting in incomplete combustion of the fuel. Carbon deposits, oil hydrocarbons and other products, unburned fuel itself and moisture condensates cause the formation of sludge, acid and asphalt. Unburned fuel falls on the cold walls of the cylinders and flows down them into the crankcase, while the oil film is washed off the walls of the cylinders and pistons. The consequence of this is the deterioration of the lubrication of the cylinder walls and the dilution of the oil, which affects the lubricating properties of the oil, depending on the amount of fuel that has entered the oil.
In case of severe dilution of the oil, it should be replaced ahead of schedule. Since with a sharp driving style (hot engine) gasoline particles evaporate in the oil, the oil level should be checked more often in winter (numerous cold starts - high proportion of gasoline in oil).
Engine oil viscosity
The viscosity of engine oil characterizes its fluidity. The viscosity of engine oil changes with temperature. As the oil heats up, it thins out. This affects the adhesion and pressure resistance of the oil film. As the oil cools, the viscosity increases, and the internal frictional resistance increases. This property requires the use of an oil whose fluidity changes little with changes in temperature.
On a cold engine, the oil must be thin enough not to obstruct the operation of the starter and to be able to penetrate all lubrication points as quickly as possible. This requires the use of an engine oil with a viscosity that changes as little as possible with temperature.
The viscosity is identical to the internal friction of the oil and is classified according to the SAE system (Society of Automotive Engineers), such as SAE 30, SAE 10, etc. High indexes are assigned to thick oils, low indexes to liquid oils. But viscosity is not a characteristic of the lubricating properties of the oil.
Application ranges/Viscosity classes
A - high-performance and low-speed oils according to VV 500 00 and 505 00 standards
B - all-weather oils according to VW 501 00 standards, oils 5 W, that is, for gasoline engines
C - seasonal oils
Universal (all season) oil
For water-cooled engines with opposed cylinder arrangement, all-weather oil must be used. Multigrade oils have the advantage that they operate over a wide temperature range (summer Winter). The basis of all-weather oil is a grade of liquid oil (e.g. 10W). Thanks to the so-called hot thickener, the oil is stabilized, thus retaining its lubricating properties under all operating conditions. When using all-season oils, you should choose modern grades of oils that have a wide viscosity range (e.g. 10W-40.1 5W-50).
Letter "W" 8 SAE designation indicates the suitability of the oil grade in winter.
Light oils
Light-running oils are multi-grade oils with an additive that reduces internal friction, which can save up to 2 percent in fuel. Lightweight oils have a low viscosity (e.g. 10 W-30). Unusual oils are used as base oils here (synthetic oils). When buying a low-speed oil, you should pay attention to whether the oil grade is approved for use by VW / AUDI.
Since the ranges of application of seasonal oils of neighboring SAE classes overlap, short-term temperature changes can be ignored. It is allowed to mix oils of different viscosity grades, if topping up is required, the ambient temperature no longer corresponds to the viscosity grade of the oil filled into the engine.
With prolonged exposure to outside temperatures below -30°C (arctic regions) It is recommended to use SAE 5W30 oil.
Additives - no matter what kind - should not be mixed into either oil or fuel.
All-weather oils of viscosity 10W50 should not be poured into the engine.
Engine oil specification
Only HD oils are allowed for modern engines. HD oils are alloyed oils whose lubricating properties are greatly improved by the addition of various chemicals. These additives provide good anti-corrosion protection, reduction of oxidation activity, especially low tendency to form sludge in the crankcase, better viscosity characteristics, cleaning and dissolving properties. Cleaning and dissolving additives not only reduce the formation of deposits in the engine, but at the same time have the ability to dissolve deposits and permanently hold in suspension and other contaminants in the engine oil, so that when the oil is changed, they drain with the old oil.
The parameters of HD oils are classified according to the API system (American Petroleum Institut). European manufacturers also follow this system.
Designations are two-letter. The first letter characterizes the range of application: S = Service is intended for petrol engines; C = Commercial, designed for diesel engines. The second letter in alphabetical order characterizes the type of oil.
The highest grades of oils are SG oils for gasoline engines and CE oils for diesel engines (according to the API specification).
Attention: Engine oils clearly marked by the manufacturer as oils for diesel engines are not suitable for gasoline engines. There are oils that are suitable for both gasoline and diesel engines. In this case, both specifications are indicated on the packaging (e.g. SG/CE).
VW has set its own oil standards for VW/AUDI models. Be sure to use only oils that meet the requirements of these standards. The VW rate is indicated on the oil canister. If in doubt, check with the dealers for the latest condition of approved oils.
Gasoline engines require high-performance oils that simultaneously meet the requirements of standards 500 00 and 505 00. Light-running oils according to VW 500 00 and multigrade oils according to VW 501 00 can also be filled. Multigrade oils according to VW 501 00 are usually more expensive. If an oil of this specification is not currently available, you can temporarily fill in seasonal or multigrade SF specification oil.
Oil consumption
In internal combustion engines, oil consumption refers to the amount of oil that is consumed as a result of the combustion process. Oil consumption cannot be equated with leaks occurring in the oil sump, cylinder head cover, etc.
Normal oil consumption is obtained as a result of combustion of a small amount in the cylinders, oil removal along with combustion and friction objects. In addition, oil wear occurs due to the high temperatures and pressures that the engine is constantly exposed to.
In addition, external operating conditions, driving style, as well as manufacturing tolerances affect oil consumption. Oil consumption should not exceed 1.0 liters per 1000 km.
When the oil drops to the level "Top up" be sure to add oil (at the same time, the volume of oil to be added is a maximum of 1 liter).
Visitor comments