How Aerodynamic Drag Affects Commercial Vehicles
Driving a commercial vehicle is like traveling in a giant brick. They’re heavy, boxy and not very aerodynamic. The bulk and sharp edges create friction against the air that travels around the vehicle, causing drag that affects how efficiently you move at high speeds. That can result in inefficiencies, including reduced fuel economy, increased tire drag and greater operational expenses. Implementing structural modifications can help reduce the effects of aerodynamic drag.
What is Aerodynamic Drag?
It’s the force that opposes an object’s motion as it travels through the air. As the air interacts with the surface of your commercial vehicle, it pushes in the opposite direction, slowing your forward projection.
Airflow travels up and over the front of your cab onto the top and along the sides of your trailer. The gap between the cab and trailer creates a pocket that sucks air inward and causes turbulence.
There are two types of drag:
- Skin friction drag: Air moves in layers, and skin friction occurs when the closest layer comes into contact with the surface of your vehicle.
- Pressure drag: Air particles become compressed when they encounter your front end.
The Effects of Poor Aerodynamics on Semis
Increased Rolling Resistance
Crosswinds and turbulence contribute to vehicle lifting, which can lead to uneven loading and heat buildup on your tires. As drag-induced movement shifts, your tires must compensate with more lateral grip to keep the cab and trailer stable. That could result in tire deformation, putting more of the tire’s surface in contact with the road and increasing rolling resistance.
Reduced Fuel Efficiency
The opposing force of aerodynamic drag makes it harder to propel your truck forward. That requires more fuel to generate enough horsepower to push against the airflow. So, the greater the aerodynamic drag, the more fuel your vehicle must consume. That can become an expensive problem if you operate a long-haul fleet or multiple vehicles. The added engine strain also contributes to heat stress and component wear, eating into system efficiency and consuming additional fuel.
Vehicle Instability
Your cab and trailer catch crosswinds like sails on a ship, generating a strong lateral force that pulls your vehicle sideways. That can be dangerous if your commercial truck has a high vertical profile and negatively impacts its stability on the road. You may even experience trouble keeping your trailer in line with the rest of your rig, which may pose a risk to other drivers. Constant steering corrections also contribute to driver fatigue, further affecting steadiness and safety.
How to Optimize Aerodynamics and Reduce Drag
Your truck’s alternator uses less power during idling, which is problematic if you’re using high-draw The following components are designed to manage drag and optimize performance:
- Roof fairings: These curved panels attach to the roof of your cab to allow air to flow smoothly from the front end around the trailer. Roof fairings also decrease the gap between your cab and trailer to help manage turbulence.
- Low rolling resistance tires: Because they provide a rounder profile and better stability, low rolling resistance tires reduce aerodynamic tire drag around wheel wells and the underbody of your semi. They also have shallower treads that aren’t as likely to trap airflow.
- Nose cones: These attachments extend the front of your cab, preventing air damming that occurs when wind hits a large, flat surface. They allow you to reshape your rig so air can part and flow more efficiently around your truck.
- Molded bumpers: Curved bumpers are better suited to directing airflow than flat, square edges. You can install molded bumpers to the underside of your front end and fender.
- Chassis skirts: Attach chassis skirts behind the cab steps to cover your fuel tank, fenders and battery and create a streamlined profile. They redirect air from below your truck to reduce turbulence and maximize fuel efficiency.
Bring Your Commercial Fleet to Bauer Built
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