What can be a consequence of using incorrect lubricants in a vehicle?

Using incorrect lubricants in a vehicle can indeed lead to damage to the emission system. Lubricants are specifically formulated to provide certain properties, such as viscosity, thermal stability, and protective additives. When an incorrect lubricant is used, it may not provide adequate lubrication or protection against corrosion and wear for engine components. This can cause excessive heat and stress on the engine, potentially leading to the breakdown of oil and the formation of sludge.

Furthermore, faulty lubrication can cause components to fail, which can result in oil leaks that contaminate the vehicle’s emission systems. Ultimately, this can impair the vehicle's ability to meet emission standards, leading to potential failures during emission testing and contributing to overall pollution.

By contrast, the other options imply improvements in the vehicle's performance, efficiency, or longevity, which would not be expected consequences of using the wrong type of lubricant. In fact, using the correct lubricant is crucial to maintaining these positive attributes in a vehicle.