They can actually improve your vehicle's gas mileage.
One of the most promising ways to improve gas mileage is through vehicle aerodynamics. Apart from reducing the weight of your truck and its cargo, there are several enhancements available to boost aerodynamics. Aftermarket accessories such as side fairings, deep-angled bumpers, trailer skirts, pickup truck bed covers, truck cab spoilers, and hood shields are phenomenal replacement parts and upgrades to boost vehicle aerodynamics!