What Does a Bonnet Scoop Do? Types, Benefits, and What to Know Before Buying

Well, maybe you’ve seen sporty and rugged-looking cars with holes in their hoods. And maybe you don’t know what they are, that’s okay because we’re here to guide you.

When you spot a car with holes in its hood, it’s called a bonnet scoop. It’s an eye-catching accessory that looks powerful and performance-driven. But beyond the bold exterior, have you ever wondered: what does a bonnet scoop actually do?

This blog dives deep into the purpose of bonnet scoops, their types, and whether they’re just for looks or a secret weapon under the hood.

What Is a Bonnet Scoop?

A bonnet scoop (also known as a hood scoop) is an air intake feature located on the vehicle’s bonnet. Its main function is to channel air into the engine bay, either to feed the intake system with cooler, denser air or to help regulate engine temperatures.

While some scoops are highly functional and designed for performance gains, others are purely decorative, that gives the 4x4 a sportier look. 

How Does a Bonnet Scoop Work?

Bonnet scoops take advantage of aerodynamics to improve engine performance. Here's how:

• Cooler air intake: Cold air is denser and contains more oxygen. Scoops allow this air to enter the intake system, improving combustion efficiency.
• Better engine cooling: Scoops help reduce engine bay temperatures, especially beneficial for turbocharged or high-performance vehicles.
• Ram air effect: At speed, air entering a forward-facing scoop is compressed and forced into the engine, creating a mild supercharging effect.

Cons of a Bonnet Scoop

While bonnet scoops can add serious flair and even performance benefits, they also have their downsides. One common issue is water ingress, as functional scoops can allow rain or wash water into the engine bay. Driving through inclement weather is hard, especially if the scoop setup lacks proper drainage. Without adequate sealing, moisture can creep in and cause problems, particularly around sensitive engine components.

Another factor to consider is aerodynamic drag. If the scoop isn't designed properly or installed correctly, it can disrupt airflow and slightly reduce your fuel efficiency. It’s not dramatic, but for those conscious of every kilometre per litre, it’s worth noting. 

Another is heat management which can also become a problem if the scoop design doesn’t actually assist with cooling. A poorly placed or blocked scoop might end up trapping hot air rather than venting it. Plus, there are the legal and insurance concerns modifications like bonnet scoops can affect your compliance with road safety regulations or even your insurance coverage, especially if they obstruct visibility or haven’t been professionally fitted.

Lastly, if you opt for a non-functional or faux scoop, know that it’s all show and no go. It won’t add performance, and if the quality is low or the installation looks off, it could take away from your car’s overall value rather than add to it. So before you jump into the scoop life, make sure you weigh the pros and cons, your ride (and wallet) will thank you.

Types of Bonnet Scoops and Their Functions

Bonnet scoops come in several styles, broadly classified into functional and non-functional. Each type has distinct characteristics:

Functional Bonnet Scoops

These scoops actively enhance vehicle performance.

1. Ram Air Intake: This hood scoop only works effectively at certain speeds, as it captures high-pressure air while the vehicle is moving and forces it into the intake. This increases oxygen intake, which improves power and throttle response which is perfect for drivers chasing performance gains.
2. Cowl Induction: Pulls cool air from the base of the windshield, where air pressure naturally builds up. It helps improve airflow and allows the engine to breathe more efficiently, especially at high RPMs. Thanks to its smart design, it’s also less likely to let rain, snow, or other elements into the engine bay.
3. Shaker Scoop: Attached directly to the engine and protrudes through a cut-out in the bonnet. It feeds cold air directly into the carburettor or throttle body. Visually, it “shakes” with the engine for a dramatic effect, and it can be loud, especially when paired with a large engine–so you’ll want to check your state’s car modification laws in Australia before fitting one.
4. NACA Duct Scoop: Originally developed by NASA (formerly the National Advisory Committee for Aeronautics), the NACA duct is a recessed air intake developed to reduce aerodynamic drag on high-speed vehicles like jet aircraft. Its clever shape deflects slower-moving boundary layer air away from the opening, allowing faster, cleaner airflow into the engine bay. While it doesn’t allow as much air volume as a raised scoop, it offers a much lower drag profile, a worthwhile tradeoff for race cars or high-performance builds where aerodynamics matter.  
5. Raised Scoop: This is your classic, aggressive-looking raised scoop that sits elevated on top of the bonnet. It allows greater airflow and better cooling for the engine, especially on turbocharged or high-heat performance cars. However, it can increase wind resistance if not aerodynamically shaped and might limit driver visibility depending on placement.

Non-Functional Bonnet Scoops (Faux or Decorative)

These scoops are added for appearance only and do not affect vehicle performance.

Faux Bonnet Scoops: Faux is a type of hood scoop focuses on enhancing the vehicle’s sporty aesthetic. It is usually made from plastic or fibreglass, easy to install with adhesives or clips, and does not have any opening to the engine at all, meaning no air intake or cooling benefit. It’s purely cosmetic.

Functional vs. Non-Functional Scoops: What’s the Difference?

Why Performance Cars Use Bonnet Scoops

Bonnet scoops are not just a flex, they're essential in high-performance and turbocharged cars that demand increased cooling and oxygen intake.

Vehicles like the Subaru WRX STI, Ford Falcon XR6 Turbo, and Toyota Hilux (certain variants) often feature functional scoops to optimise airflow and keep engine components at safe operating temperatures.

Should You Add a Bonnet Scoop?

Thinking of installing one? Consider the following:

• ✅ Performance Need: If you drive a high-powered or turbocharged engine, a scoop can help.
• ✅ Aesthetic Appeal: Even decorative scoops can enhance your car’s exterior if you want your car of 4x4 to look sportier and it brings out the angst of your car.
• ✅ Quality Matters: Every car accessories should be made from high quality materials that are durable and UV-resistant scoops. It should also come from trusted auto accessory suppliers.

If you're serious about style and performance, Ausgo offers premium aftermarket bonnet scoops and body kits tailored to Australian conditions. 

You can also consult your local mechanic or auto body shop if you're thinking of adding a hood scoop to your vehicle. They’ll help you figure out what suits your engine and what to buy and you can check out the range of bonnet scoops available at Ausgo.

Just remember to compare the different types before buying. Functional scoops can cost more but offer real performance benefits. But if you're just looking to flex and give your car that aggressive, head-turning look, you can opt for a faux scoop instead.

Whether you're chasing horsepower or just turning heads, there's a bonnet scoop for that!