Car spoilers - what are they, what are they for, and how are they designed?

Contrary to what you may think, car spoilers are not just a characteristic element of the body of sports and racing cars. Their advantages make them also applicable to passenger cars, which can be found on the streets every day. Car spoilers perfectly combine aesthetics and functionality. They provide vehicles with additional visual appeal while at the same time increasing their aerodynamics.

There are several types of spoilers, differing mainly in shape, the material they are made of, and the place of fixing. However, irrespective of the type of spoiler, the specialists working on its design must take into account such factors as safety, appropriate production technology, or aesthetics, among others.

Car spoilers are undoubtedly a fascinating subject that arouses great interest among many car enthusiasts. If reliable information and the latest news from the automotive world are also close to your heart, then the rest of this article will provide you with a really solid dose of knowledge. Among other things, we explain what car spoilers are, why they are used, what they are made of and the design process for these body parts.

What are car spoilers?

An important area to take care of in the design process of a car is its exterior components. This is a broad group of parts, including bumpers, mirrors, grills, overlays, and the solution we will focus on today, car spoilers.

What is a car spoiler? This term is used to describe an aerodynamic component whose primary task is to manipulate the air flow around the car body in such a way as to improve the vehicle’s aerodynamics and handling characteristics. How does this happen? The spoiler helps to reduce the pressure difference occurring between the zone above the car and the zone extending below it. This is beneficial in ensuring the car’s handling stability and the appropriate level of wheel grip on the road.

A high pressure differential between the areas above and below the vehicle can generate undesirable upward load forces, which negatively affect the car’s road behaviour. The value of this force increases with increasing vehicle speed. The use of a car spoiler contributes to an increase in the car’s pressure on the road surface, so that its handling characteristics, especially at higher speeds, are noticeably improved. For this reason, the functional side of spoilers is usually of interest mainly to:

• sports car owners,
• drivers who frequently drive outside built-up areas, where they can travel at much higher speeds than 50-60 km/h.

At standard speeds, which can be reached in, e.g.: a city, the effects related to the improvement of the car’s handling characteristics as a result of using a spoiler are negligible. The primary purpose of spoilers on ‘city’ cars is therefore usually to make the vehicle more visually appealing.

Car spoilers vs. other aerodynamic elements in the vehicle

Although many people colloquially refer to the various external aerodynamic elements on a car as ‘spoilers’, in professional language, the term ‘spoiler’ has a more specific meaning. The attachment of a spoiler is usually made directly to the upper edge of the rear of the body – in the case of sedans, the place of installation is usually the end of the boot, while in hatchbacks, the spoiler is usually attached to the end of the roof, although it is also possible to use an analogous installation method as in sedans. Special aerodynamic elements can also be fitted at the front, whereby the front bumper spoiler already has a separate name and is referred to as a splitter.

Another interesting solution is the so-called ‘wing’, which is distinguished by its considerable distance from the car body. Special brackets are used to achieve this effect. The name ‘wing’ alludes to the resemblance to an aircraft wing, but the important difference is that in the case of car components, they generate a downward, rather than an upward, lifting force. As a result, the car is not lifted but is pressed aerodynamically against the road surface.

What functions do car spoilers play in cars?

Once we know what car spoilers are, we can move on to discuss the roles they play in cars and the benefits of using them.

• Improving aerodynamics and grip

Rear spoilers aim to provide vehicles with the right aerodynamics and grip. Rear spoilers make the car easier to steer at higher speeds – the car has better grip and stability, and the unwanted ‘roll’ effect is reduced.

• Reduced fuel consumption

From a functional perspective, car spoilers also provide other benefits, such as slightly lower fuel consumption when travelling at high speed or a reduced risk of losing control of the vehicle as a result of skidding.

• Aesthetics

As we pointed out earlier, however, the effects associated with improved driving properties are to be guaranteed primarily by sports spoilers, which are fitted to cars intended, for example, for track use. So it is worth asking ourselves: why a spoiler in a passenger car if its effect may be hardly noticeable at standard speeds? The answer is simple: aesthetics! For a large number of drivers, the visual aspects are just as important as the functional aspects, which is why a skilfully designed spoiler, matched to a given model, can be a really strong argument convincing a potential customer to buy a car. Typically, spoilers are designed to emphasise the car’s sporty character and dynamic styling. In order to achieve an even more impressive result, a car spoiler and car manufacturer may decide to install a so-called bodykit, i.e. a kit that includes not only the spoiler but also, for example, special bumpers and side sill overlays. In this way, it is possible to market vehicles that are standard engine versions with sporty body parts.

What materials are used to make car spoilers?

The manufacturer of spoilers dedicated to both passenger cars and sports cars has a wide range of materials to choose from when producing these components. The choice of material has a key impact on both the technical characteristics of the spoiler and its price. What materials are most commonly used to manufacture spoilers for cars?

Laminate – a combination of glass fibre and resin

The most common car spoilers on the market are made of laminate, which usually uses fibreglass and resin to create them. Such a material is obtained from glass melted at temperatures as high as 1,200 degrees Celsius and then subjected to appropriate curing processes, including the addition of resin. This spoiler manufacturing technology is quite simple and inexpensive, which is why the exterior components produced in accordance with it are among the cheapest and most popular.

It is worth noting that they are very popular with drivers who dream of inexpensive car tuning. Due to the large availability of laminate spoilers on the market, choosing the right solution in terms of colour, design, and shape for a specific car model is not a big problem. The big disadvantage of spoilers made of this material, however, is their low impact resistance.

Polyurethane

Are there other materials that can be used for spoilers? One popular choice is polyurethane, which is characterised by its durability, flexibility, and significantly higher impact and scratch resistance compared to laminate. Because of this, spoilers made of polyurethane are noticeably more expensive than those made of laminate.

Thermoplastic materials

Another group of materials that a car spoiler manufacturer can rely on are thermoplastics, such as ABS. Characteristic features of spoilers made of ABS include high resistance to mechanical damage as well as the negative effects of high temperatures. The most significant disadvantage of external components made from ABS is their increased weight.

Composites

Individually designed bespoke car spoilers, or those that adorn more expensive car models, are usually made from composites. Of the composites used for spoilers, carbon fibre, sometimes also referred to as carbon fibre, is particularly popular. Aerodynamic elements made on its basis are distinguished by, among other things:

• very low weight
• high resistance to mechanical damage,
• a unique design that combines elegance and sportiness.

Luxury car spoilers made of carbon fibre are undoubtedly a premium solution – they cost significantly more than parts made of other materials, but they are extremely functional and look great.

Designing car spoilers – what should be taken into account?

Correctly designed car spoilers should be distinguished by certain features that will provide these external elements with an appropriate level of safety, aesthetics and functionality. What should be taken into account when designing these car parts, and are such solutions always legal?

• The use of car spoilers is perfectly legal, provided they meet a few basic criteria. Car spoilers must be free of sharp, dangerous edges that could pose a danger to pedestrians and other road users. Care must also be taken to ensure that the spoiler is properly attached to the vehicle – special, very strong adhesives and screws are usually used for this purpose.
• An important issue in the context of designing car spoilers is striving for the lowest possible weight of such elements. Thanks to their lightness, it is possible to reduce fuel consumption as well as exhaust emissions. In order to provide spoilers with low weight, designers have to face several challenges, such as reducing the number of parts that make up the spoiler structure or limiting the wall thickness while maintaining the required level of durability.
• Reducing the number of components used in the production of a spoiler not only affects its lower weight but also reduces the cost and production time of such a component. Companies that care about maintaining production profitability must therefore look at the issue of minimising the number of spoiler components from this angle as well.
• The key to the success of spoilers on the market is the selection of the right production technology. The design of the component must take into account that the part can be efficiently manufactured using, for example, plastic injection moulding. The shape of the designed structure should be routed in such a way that no so-called suction or mould splitting occurs during injection moulding. This will ensure that the resulting part retains the required durability, safety and aesthetics. Care must also be taken to ensure that the wall thickness of the manufactured parts is maintained – this will avoid visible deformations and other defects.
• When designing spoilers for a car and other car exteriors, attention must be paid to the issue of proper aerodynamics. The industrial design of such parts must take into account that they should reduce air resistance and improve airflow around the car. The optimum shape and smoothing of spoiler surfaces can help reduce fuel consumption and noise, among other things.
• Designing car components, including spoilers, also requires a focus on aesthetics. Spoilers should not only blend harmoniously with the character of a specific car model but also add to its attractive appearance. Stylishly designed exterior elements are one of the important factors in determining a vehicle’s positive perception and generating interest in it from potential buyers.

What is the process for designing car spoilers at Endego?

At Endego, we specialise in the design of car spoilers and other car exteriors, which are collectively classified as Exterior. We have unique know-how and extensive experience in this field, resulting in more than a decade of successful technology projects in collaboration with leading automotive companies. How does the process of designing car spoilers proceed in our execution?

The initiating stage in the design of a car spoiler is the Concept Studies phase. In this phase, our team of specialists, among other things:

• identifies the customer’s needs and requirements,
• makes a comparative analysis of other solutions available on the market,
• carries out a selection of materials that will enable the spoiler to best fulfil its function.

The findings from the Concept Studies phase lay the foundations for further design activities.

The next stage in the comprehensive development of a car spoiler is design. This includes a number of activities related to, among other things:

• parametric CAD modelling,
• calculation of the tolerance chain,
• CAE analysis,
• verification of design feasibility,
• preparation of comprehensive documentation.

During the design work, we pay particular attention to ensuring that the developed element is characterised by lightness, durability, possibly low-cost production, and exceptional aesthetics, which will harmoniously fit into the styling of the car model to which the spoiler is to be attached.

Successful implementation of the design activities allows us to move on to the final phase of complex product development, namely prototyping. This takes place in prototyping loops, which consist of:

• creation of the 3D model,
• production of the prototype,
• assembly of the prototype,
• validation of the prepared model.

The prototyping cycle is repeated until we obtain the approval of a satisfied customer for the proposed version of the solution.

Our comprehensive approach, with full involvement in every stage, from the development of the initial concept to the start of serial production, ensures the final success of the entire project. It is worth noting that at all stages of complex product development, in this case an automotive spoiler, we guarantee our partners expert technical advice, including on-demand support.

Are you looking for a team of qualified engineers with extensive experience in the automotive sector to help you create a spoiler that perfectly matches the characteristics of the car your company is designing? Don’t wait – contact us now! Your perfect spoiler is at your fingertips.