Which maintenance practice helps prevent injector fouling?

Preventing injector fouling is crucial for maintaining optimal engine performance, and the combination of using premium fuel and regular oil changes plays a significant role in achieving this.

Using premium fuel can be beneficial because it often has a higher octane rating and lower levels of impurities compared to regular fuel. This can lead to cleaner combustion, resulting in fewer deposits forming on the injectors. Premium fuels may also contain additives designed to help clean the fuel system, further reducing the likelihood of fouling.

Regular oil changes are also essential as they help maintain engine cleanliness. Fresh oil is more effective at lubricating engine components and reducing the buildup of contaminants, including those that can lead to injector fouling. Over time, oil can degrade and become contaminated with soot and other combustion byproducts, which can impair both the oil and the fuel system.

Therefore, the combination of using premium fuel and performing regular oil changes together contributes significantly to reducing the risk of injector fouling, making the selected answer correct. Frequent engine tuning can help maintain engine performance but is not as directly related to preventing injector fouling as the other two practices.