Car Bottom Plastic: How Much Protection Does It Offer?

The plastic undercarriage cover is a common feature of modern vehicles, designed to protect wires and sensors. This plastic is typically found around drivetrain components at the front and middle of the chassis. However, some people question the importance of this plastic, with one user on MetaFilter noting that a 3mm plastic guard won't protect against curbs or rocks. Another user on the same site refers to the plastic as an 'engine splash shield', which helps to smooth the flow of air under the car and can impact gas mileage and noise levels.

Plastic undercarriage covers are designed to protect wires and sensors

There are different types of plastic undercarriage covers. Some are thin, around 3mm, and won't protect against curbs or rocks. Others are thick, heavy, and substantial. One type of plastic undercarriage cover is the engine splash shield, which helps smooth the flow of air under the car. Without it, you may experience a slight decrease in gas mileage and increased noise at highway speeds.

Skid plates are a type of plastic guard that protect against curbs and rocks

Skid plates are often made of UHMW plastic, which is resistant to high impacts and low friction. This material does not corrode and is extremely lightweight. However, plastic skid plates may not be suitable for protecting against curbs, rocks, or similar obstacles. Steel is the hardest material commonly used for skid plates and provides excellent protection. However, it can add significant weight to your vehicle and compromise fuel efficiency.

In addition to skid plates, modern vehicles often have plastic undercarriage covers to protect the wires and sensors included with newer cars and trucks. These covers are typically found around drivetrain components at the front and middle of the chassis. While they are not as durable as skid plates, they help smooth the flow of air under the car and can improve gas mileage.

Overall, skid plates and plastic undercarriage covers are important components of modern vehicles, providing protection against various obstacles and ensuring the safe operation of the vehicle.

Engine splash shields help smooth the flow of air under the car

Engine splash shields, also known as skid plates, are designed to protect the underside of a vehicle's engine and other important components from water, corrosive materials, and road debris. They are usually made of plastic, which can become fragile when cold, making them susceptible to damage when driving over road debris, packed snow, or even when parking over a high curb.

One of the key functions of an engine splash shield is to help smooth the flow of air under the car. By channelling airflow to other underbody components, the shield keeps them from overheating and helps reduce drag for a smoother and quieter ride. This also improves fuel economy and reduces wind turbulence within the engine compartment.

Engine splash shields are particularly useful for 4x4 vehicles or other off-road vehicles when driving on rough terrain. They can also be considered performance or aesthetic upgrades.

Without an engine splash shield, you may experience a slight decrease in gas mileage and the car may be noisier at highway speeds.

Plastic guards can be as thick as 3mm

Plastic guards are typically found around drivetrain components at the front and middle of the chassis. They are designed to protect the wires and sensors from being snagged by branches or road debris, which could sever a wire or disconnect a crucial component.

One user on MetaFilter noted that their plastic guard was "thick and substantial and quite heavy". This suggests that while some plastic guards may be as thin as 3mm, others can be significantly thicker and heavier.

It is worth noting that these plastic guards are not always effective at protecting against curbs, rocks, or similar hazards. In some cases, a thicker or more durable material may be required to provide adequate protection for the underside of a vehicle.

Plastic undercarriage covers are found on almost any modern vehicle

Undercarriage covers are designed to protect the wires and sensors that are included with newer cars and trucks. With cables that hang down and sensors that stick out, there's always a chance that a branch or road debris will snag something important and sever a wire or disconnect a crucial component.

One user on MetaFilter referred to the plastic undercarriage cover as a "skid plate", and noted that a 3mm plastic guard won't protect against curbs, rocks or the like. Another user referred to the plastic under their car as an "engine splash shield", which helps to smooth the flow of air under the car. They noted that without it, they experienced a slight decrease in gas mileage and increased noise at highway speeds.

The amount of plastic undercarriage cover on a car can vary depending on the make and model of the vehicle, as well as the specific components that are being protected.

Frequently asked questions