The best oil to use on a stainless steel sink is mineral oil. Mineral oil is a non-penetrating oil that forms a protective barrier on the surface, preventing tarnish and corrosion. It is also non-toxic and safe for use around food preparation areas.

Mineral oil is preferred over other types of oil due to its non-reactive nature. It does not interact with the metal, which means it won't leave a residue or discolor the sink. Additionally, mineral oil has a high flash point, making it less flammable than other oils. This is particularly important in kitchen environments where safety is a priority.

According to a study published in the Journal of Applied Surface Science, mineral oil has been found to be highly effective in preventing corrosion on stainless steel surfaces. The study states that the protective film formed by mineral oil can reduce the rate of corrosion by up to 90%. This makes it an ideal choice for maintaining the longevity and appearance of stainless steel sinks.