It's time to check the antifreeze

Summer is coming to an end and it's time to prepare our cars for the cold months. This necessarily includes checking the coolant level. But in this seemingly simple task, unfortunately, very often serious mistakes are made.

Back in the day, topping up antifreeze was a really simple task because there was no choice on the market, and even when there was, they were all the same formula. Now that is not the case. There are at least three chemically different types of antifreeze on sale, which are incompatible with each other - if you need topping up, you have to be very careful to hit the right composition. Mixing two different types can destroy the radiator and cooling system.Apart from that, over time, antifreeze loses its properties. Therefore, depending on its type, it should be completely replaced every two to every five years. Continuous topping up for a longer period can lead to unwanted deposits on the system and radiator.Practically all types of liquid for the cooling system are a solution of ethylene glycol (or, in the most modern, propylene glycol), and water. The big difference comes from the added "corrosion inhibitors", that is, the substances that protect the radiator and system from rust.At the time, IAT-type fluids dominated, with inorganic acids as corrosion inhibitors - initially phosphates, and later, for environmental reasons, silicates. Cars over 10-15 years old are usually adapted for such. However, IAT antifreeze only lives for about two years and then needs to be replaced.More modern cars are adapted for OAT type antifreeze, in which silicates are replaced by azoles (complex molecules containing nitrogen atoms) and organic acids as corrosion inhibitors. They are more durable - usually up to five years.There are also so-called HOATs, or hybrid liquids, which are essentially a combination of the first two types, with silicates and nitrites at the same time. Carboxylates are also included in the formulas approved in the EU. They are suitable for more extreme conditions, but also have a shorter life and require more frequent replacement.Each of the three types is incompatible with the others.Antifreeze's color comes from the added colorant, not its chemical formula. Some manufacturers use color to indicate the type - eg green for IAT, red for OAT, orange for HOAT.With G11 (blue), the basis is ethylene glycol, which is diluted with distilled water and various inorganic additives. It is mainly used in cars manufactured before 1996. In many countries, ethylene glycol is restricted for use because it is harmful to humans and the environment.The products of the G12 series (red) were developed for cars manufactured after 1996. and meet the requirements of modern engines. They are also based on ethylene glycol, but with completely different additives - organic substances, carboxylates, silicates.BMW does not give specific approvals for the coolant to be used in the cars it manufactures, unlike engine oils with BMW Longlife approvals or transmission oils. The reason for this is obvious:There is only one BMW OEM coolant.BMW radiator antifreeze concentrate is colored blue-green.For BMW, the coolant number used is BMW 83512355290 or an alternate part number such as BMW 83192211191. In both cases, this is the reference number of the antifreeze concentrate for BMW radiators.The recommended mixing ratio is 1:1 with water to provide cooling down to -40 degrees. A 1:1 mixing ratio means that the finished coolant consists of equal parts, i.e. 50% and 50% coolant concentrate and water.Experts strongly recommend adding distilled water, because there are too many impurities in ordinary water, which are deposited on the walls of the pipelines and the radiator. The dilution ratio depends on the specific type of antifreeze and the conditions in which you will use it - lower temperatures require less diluted coolants.If you want to have peace of mind about your beloved BMW and prepare it properly with new antifreeze - contact the experts in the industry: Auto Motor Parts Group Ltd.

source : BMW GROUP