Which is the least expensive service listed?

The least expensive service listed is the fuel system cleaner. This service typically involves the use of a specialized cleaning solution that removes deposits and grime from the fuel system, including fuel injectors, intake valves, and combustion chambers. It is a preventative measure that enhances engine performance and efficiency, often offered at a competitive price point.

In contrast, the other services mentioned usually involve more extensive materials or labor. Aquapel glass treatment is a specialty product designed to enhance visibility and safety during adverse weather conditions, often priced higher due to the quality and effectiveness of the treatment. Both additional semi-synthetic oil and additional synthetic oil services relate to oil changes, which can be costlier due to the higher quality of synthetic oils compared to conventional oils. Therefore, the fuel system cleaner stands out as the most economical option when considering the common pricing structure for automotive services.