Aluminum strips, when used in the context of vehicle fuel efficiency, typically refer to the use of aluminum in vehicle construction to reduce weight. Aluminum is a lightweight material with high strength, which can significantly decrease the overall weight of a vehicle. By reducing the weight, the engine doesn't have to work as hard to move the vehicle, leading to less fuel consumption. Additionally, lighter vehicles can accelerate and decelerate more quickly, which can also contribute to improved fuel efficiency. However, it's important to note that the impact on fuel efficiency can vary based on the vehicle's design, driving conditions, and other factors.