FAQ – Frequently asked Questions

On average, around ca. 150 liters of coolant are pumped around the cooling system of a car engine each minute, and commercial vehicles have a much larger cooling system. The mixture of water and coolant can come into contact with up to a hundred different materials. Unless the correct engine coolant is selected, the high temperatures and high pressure drop in the system create ideal conditions for rust and cavitation. Without any protection, the cooling water can etch deep holes into the metal and damage the cylinder head, cylinder liners and water pump. This can cause the cooling system to fail and can even damage the engine beyond repair.

Motor manufacturers have very specific demands on the performance of engine coolants, depending on which materials they come into contact with. Mobil OE Approved Coolants has been working in close cooperation with all leading motor manufacturers for many decades and has developed a suitable product for every engine.

Mobil OE Approved Coolants increases the boiling point of the cooling water to around 110 °C. Mixtures of water and Mobil OE Approved Coolants can absorb more heat than pure water without boiling. Mobil OE Approved Coolants is also very effective for preventing scale formation in cooling systems. Scale quickly tends to block the narrow channels in the system and prevents heat from being transferred to the ambient air. This can easily lead to overheating in the summer months. Mobil OE Approved Coolants also performs very effectively as an antifreeze.

The color of the coolant is defined in the specification from the vehicle manufacturers and is also a small but important part of the official approval from the vehicle manufacturers.

Important note: By the color alone, it is not possible to identify the engine coolant. The color of the engine coolant does not define the chemical and technical properties.

Coolants have to be changed every three to four years depending on the product. This is important, because the additives contained in coolants are gradually broken down. Coolants retain their antifreeze action for a long time, but the corrosion inhibitors break down over time and no longer protect the cooling system from damage.

No. Coolants are chemical substances and they often become contaminated after years of service in the cooling system. Pouring them into the drains is an offence against waste disposal legislation and is punishable by law.

No. Concentrated coolants such as Mobil OE Approved Coolants always have to be diluted. Undiluted products do not have sufficient capacity to absorb the heat from the engine, which leads to overheating. Undiluted coolants can also freeze in winter.

When you are changing the coolant, we would always recommend that you dilute Mobil OE Approved Coolants products with water at a ratio of 50:50 in order to obtain the best possible protection from corrosion, overheating and frost. The concentration of Mobil OE Approved Coolants should be no less than 33 % and no more than 60 %.

Normal tap water can mostly be used to dilute coolants if not harder than 3.5 mmol/l or contains chlorine etc. We recommend to use demineralized or distilled water.

Mixing different engine coolants or using the wrong coolant can impair the performance of the special additive packages, and this can result in increased corrosion to the radiator. The passive layer in the cooling system gradually becomes thinner and more porous and the engine coolant needs to be changed at more frequent intervals. Using the wrong engine coolants can gradually lead to corrosion and damage to the water pump, radiator, radiator hoses and cylinder gasket. This can lead to engine failure in the worst case.

Engine coolant additives such as the pH buffer are gradually broken down and become less effective with age. We therefore recommend a complete change of coolant every three to four years. It is also strongly recommended to clean the cooling system and completely renew the coolant whenever a repair is made to the cooling system. This prevents the rust, soil and suspended particles left behind in the system from causing scale, corrosion and other damage.

Officially approved engine coolants can be changed during the guarantee period without affecting the motor manufacturer’s warranty. However, filling the cooling system with unapproved coolant or antifreeze during the guarantee period can render the manufacturer’s warranty invalid.

Motor manufacturers do not “recommend” any particular engine coolants, but they do grant official approvals. New vehicles are usually filled with approved engine coolants when they leave the factory and they can be replaced during the guarantee period without affecting the manufacturer’s warranty. On average, engine coolants have to undergo thirty different tests before they are approved by motor manufacturers. These mainly consist of various different corrosion and compatibility tests with the original components of the cooling system. Motor manufacturers do not give official approval to coolants until they have passed all the tests. The process takes three to five years and it is very expensive. The coolant has to go through the entire approvals procedure again every time a change is made to the formulation. Mobil OE Approved Coolants have the most approvals from leading motor manufacturers.

Mobil OE Approved Coolants products have a shelf life of at least three years from the date of manufacture in their sealed original packaging. Its service life after it has been diluted with water depends on the vehicle manufacturer’s specifications. We generally recommend changing coolants every 3-4 years.

Mobil OE Approved Coolants contains ethylene glycol (ethanediol), which is harmful if swallowed. Contact with the skin and eyes must be avoided. Mobil OE Approved Coolants must be kept out of the reach of children and pets. If you do swallow Mobil OE Approved Coolants, you should seek medical attention immediately and show the doctor the packaging or label. You can also obtain qualified assistance by calling the emergency telephone number that appears on the Mobil OE Approved Coolants packaging.

Mobil OE Approved Coolants products can be mixed with each other, but we do not recommend this. Each product contains a different combination of additives that are compatible with the different materials in the cooling system. Mixing different additives can impair their overall performance and reduce the level of protection.

We do not recommend mixing Mobil OE Approved Coolants products with other coolants. The formulations of different products vary widely, and mixing them can lead to severe compatibility problems.

We do not recommend using Mobil OE Approved Coolants products for any purposes other than those for which they are intended. Mobil OE Approved Coolants products are developed and tested for use in automotive cooling systems. We do not usually have any information on using Mobil OE Approved Coolants in other applications.