BMW 3 Series E30

since 1983-1994 release

Repair and operation of the car

This and similar to it questions interest many motorists. The answer to the first – unfortunately, no, even if it oils of firms "with a world name" (Shell, Mobil, British Petroleum). Each firm produces commodity oils, adding the whole complex of additives which chemical composition is kept a big secret to an oil basis. Therefore, there are a lot of qualitative oils of identical appointment made according to requirements of rather ekpluatatsionno-technical properties of the international classification of API and the CCMC-ACEA European specification, but on technologies of various firms when mixing are capable to create mixes of poor quality owing to interaction and mutually destruction of additives, that is "incompatibility" of additives. Oils of different firms are interchanged, about a possibility of use of such oils engine builders often specify. But it does not mean that they can be mixed. Classification of API and the ASEA specification assume obligatory identical test methods (laboratory, bench – motor etc.) oils of different firms. At desire (or need) engine builders can enter additional tests (or more severe conditions) to these classifications.

The same treats mixing of mineral or synthetic oils (sometimes – even one firm). Oils synthetic can have structure of hydrocarbonic character (in such cases of oil of one firm it is possible to mix on what the firm producer of oil makes recommendations and what it bears responsibility for), other chemical composition. Unfortunately, cases when when mixing oils their quality worsens are frequent. As a result of it can "begin to knock" the engine as mix of incompatible oils turns into "jelly".

Even more negative answer to a question of a possibility of mixing of import and domestic oils, especially those which are made with additive of "domestic" additives. Neither the seller, nor the consumer know composition of additives which are in oils. Some oils of "a domestic origin" are produced by the "firms" which do not have even elementary knowledge of oil products. Sometimes such "experts" use the fulfilled oils (even without appropriate regeneration) to production of "commodity". At the same time and corresponding quality. Therefore advice concerning a possibility of mixing of oils should be given very carefully!

No "cleaners" (Tokron, etc.) are capable to increase gasoline octane number. For this purpose use special additives – anti-detonators which add in the course of production of gasoline at the petroplants, or additives. Deposits in the combustion chamber can be the detonation reason (the metal knock in operating time of the engine is heard) and kalilny ignition (the engine continues to work at the switched-off ignition).

Increase in a compression in the system "at introduction of some additives" happens not at the expense of viscous additives as they do not incorporate them, and for other reasons. But it is already a subject of a separate conversation.

To reduce oil waste in the old engine and to raise a compression in cylinders due to use of high-viscous oils it is inexpedient, it will lead a poskolya at first really to increase in a compression in cylinders, but for a while. Further repair of the engine will be more expensive.

Its wear is the reason of "acoustic noise" in the old engine. Therefore, repair with the subsequent use of high-quality oil will cost cheaper. It is possible "to reduce" gaps additives, but it is necessary to understand expediency of it not to do much harm to the engine.

Now concerning "ship oils" and a possibility of their use in "road diesels". There are different oils. Special ship oils for diesels concern to group E, for example, of M-16E30, M-16E60, M-20E60 intended for the low-reverse diesels using high-sulfuric high-viscous fuel – fuel oil. These oils have technical and operational properties (quality indicators) different from indicators of quality of oils of "road" diesels therefore their use in automobile diesels is impossible. There are ship oils of group D, for example, of M-10DTsL20, M-14DTsL20, M-14DTsL30 which are used in the diesels using high-sulfuric fuel. Oils waterproof, but have the raised alkaline number and a high ash-content. For "road", that is automobile diesels it is the increased wear of the engine which can not pay off free oil over time. M-16DR oil for ship diesels which use distillate fuel – diesel fuel with the increased viscosity compared with viscosity "automobile" and the content of sulfur up to 0,5%, can be used in "road" diesels in the summer (for "heavy" cargo, but not cars).

It is necessary to take for the rule: to use the high-quality oil of one brand corresponding to the engine (on classification) and not to risk to mix it with same synthetic (or semi-synthetic) oil. The engine will thank for it reliable work. Do not buy oil privately as it is easy to forge packing.