شاخصی که در روغن اجازه میده روغن دوام بیشتری داشته باشه و تو دوره بالاتری عوض بشه و با خاصیت اسیدی گوگرد موجود در بنزین های بی کیفیت ایران بتونه مقابله کنه عدد TBN هست.
ایمیل زیر رو از طرف ادینول برای پاسخ به نیاز یک کاربر بی ام و سوار در ایران به جناب مهندس یزدی فرستادند :
فایل پی دی اف :
SUPER LIGHT 0540
Engine oils for BMW cars:
a) “BMW Longlife-01” (LL-01)
– This quality is the minimum requirement for all BMW gasoline engines from model year 2002 and for BMW diesel engines without particle filters from model year 2003.
– All older BMW engines can use this quality.
– For BMW M GmbH engines, this quality is only permitted in new, designated models with S55 or S63 engines.
- b) “BMW Longlife-04” (LL-04)
– These oils are permitted for all BMW diesel engines with or without particle filters.
– This quality also applies to BMW gasoline engines. At present, the type approval is limited to the EU area together with Norway, Switzerland and Liechtenstein.
– For BMW M GmbH engines, this quality is only permitted in new, designated models with S55 or S63 engines in the EU area together with Norway, Switzerland and Liechtenstein.
That means out of the EU area together with Norway, Switzerland and Liechtenstein the use of “BMW Longlife-01”-oils are recommended, except for BMW diesel engines with particle filters.
For BMW diesel engines with particle filters “BMW Longlife-04”-oils have to be used.
Knock and Octane Number (ON)
Knock is an abnormal combustion phenomenon that occurs in spark-ignition engines. Under normal operation, combustion of the air-fuel mixture within the engine cylinder is initiated by a spark and a flame front starts to propagate outwards. If the pressure and temperature of the unburned air-fuel mixture (ahead of the propagating flame front) reach high enough levels, spontaneous auto-ignition may occur in certain spots. This auto-ignition causes an extremely rapid release of much of the chemical energy stored in the unburned mixture, resulting in large pressure oscillations in the cylinder. In turn, these oscillations produce an audible metallic “pinging” sound and if severe enough, they can cause major damage to engine components.
Due to the potential harm it can cause to engines, knock is a fundamental limiting factor in engine design.
Specifically, certain parameters have to be adjusted to avoid knock for a given fuel quality such as:
– Engine compression ratio
– Spark timing
– Boost levels:
Adding a turbocharger (boosting) forces more air and proportionally more fuel to enter the combustion chamber, so that more power can be produced by an engine of a given size. However, doing so increases the peak pressures inside the cylinder causing the engine to be more prone to knock. Consequently, boosted inlet pressure levels are limited. Turbocharged vehicles usually also have smaller compression ratios than normal, naturally-aspirated vehicles to offset these higher peak pressures.
The octane number (ON) is the standard performance measure of a fuel in terms of how resistant the fuel is to auto-ignition and knock. Raising the ON reduces knock constraints, so that new spark-ignition engines can be designed with greater compression ratios and boost levels for better fuel efficiency.
Octane number (ON) as well as knock cannot be influenced by the used engine oil.
TBN (Total Base Number)
Fuel contains some amount of sulfur. How much depends on the amount of sulfur in the crude oil from which it was produced and/or the refiner’s ability to remove it.
If the fuel will be burned inside an engine also the sulfur will be burned and in result acidic compounds – namely sulfurous and sulfuric acids – are formed. Those acidic compounds are highly corrosive compounds. One of the functions of engine oil is to neutralize those acidic compounds in order to avoid any corrosive damage to the engine. Additives (primarily detergents) in the oil contain alkaline compounds which are formulated to neutralize these acids. The measure of this reserve alkalinity in an oil is known as its TBN. Generally, the higher the TBN value, the more reserve alkalinity or acid- neutralizing capacity the oil contains.
Weather condition, high pollution, traffic jam
Engine jacket water outlet temperature influences the formation of corrosive acids. Even when using a fuel with less than 0.5% sulfur coolant temperatures below 82.2° C can cause acid vapors to
condense in the engine oil system and corrosive attack occurs. Low temperatures also increase the amount of water condensation which otherwise might have evaporated out of the oil at normal operating temperature. This residual water depletes certain oil additives and reduces the oil’s ability to protect engine parts. This causes deposits, sludge formation, lacquering, varnish and carboning. In applications where humidity is high, acids are more likely to form because of the additional water in the air. So, both low coolant temperature and high humidity can result in increased corrosive attack.
Dust and dirt from the environmen can be sucked into the engine together with the air needed for the combustion process. In order to reduce the sucked in amount of dust and dirt a car is equipped by an air filter system. So a proper working air filter is a precondition for high engine cleanliness. Particles which are passing the air filter system may enter the engine oil. In case of modern engine oils those contaminats will be kept in suspension by special additives (namely detergents and dispersants) containing in the engine oil and subsequently they are transported via oil flow to the oil filter system.
So in dusty areas both filter systems – air filters as well as oil filters – should be checked regularly.
Additionally to the comments above I also attached the Addinol Lubricant Glossary to this email. May be this documents can also help to clarify some further questions.
ADDINOL Lube Oil GmbH
Dr. Peter Thiel
Department Application Technology
Am Haupttor, 06237 Leuna, Germany
Phone: + 49 (0) 34 61/ 845-227
Fax: + ۴۹ (۰) ۳۴ ۶۱/ ۸۴۵-۵۶۱