By specialty we mean products that are not cataloged as lubricants but are still necessary for the function of an engine. The specialties available for marine line engines are coolants. The task of the coolants is to cool the engine when it overheats due to use. Three types of products are commercially available which are:

• Blue colored liquid. It is a product now almost out of use, it is used in dated engines, which need basic PH to counteract the corrosion of the glycol, moreover it cannot be mixed with other types of coolants, finally its composition based on otrites and phosphates are harmful to the environment.
• Red colored liquid. Product composed of organic fluids, it is phosphate-free, therefore not harmful to the environment and is ideal for high-performance engines.
• Yellow colored liquid. Latest generation product, which can be mixed with the red liquid, as the additives used are compatible with each other