What are the potential consequences of using poor-quality fuel in DTNA engines?

Using poor-quality fuel in DTNA engines can lead to several adverse effects, which is why the choice highlighting reduced performance and increased emissions is the correct answer. Poor-quality fuel often contains contaminants and improper additives, which can disrupt the combustion process, leading to engine knock or misfire. This situation can result in a noticeable decline in engine performance, causing issues like reduced power output and responsiveness.

Additionally, when the fuel quality is subpar, it can lead to incomplete combustion. This inefficiency not only degrades engine performance but also contributes to increased emissions of harmful pollutants such as unburned hydrocarbons, nitrogen oxides, and particulate matter. The increased emission levels can violate environmental regulations and contribute to air quality issues, which is a significant concern for modern engines that are designed to operate efficiently and within strict emission limits.

The other potential outcomes — improved fuel efficiency, enhanced engine lifespan, and lower maintenance costs — are not associated with the usage of low-quality fuel. In fact, often, poor-quality fuel can lead to higher maintenance needs due to increased deposits buildup, requiring more frequent servicing or repairs, and may even shorten the lifespan of engine components.