What do you need to know about positive and negative wheel camber?

Wheel camber is one of the most important aspects of a vehicle’s suspension geometry, significantly impacting handling, tyre wear, and overall performance. While many drivers might notice cars with noticeably tilted wheels, particularly in modified vehicles, the science behind camber angles is often misunderstood. This article explores the differences between positive and negative camber, their effects on vehicle dynamics, and the legal considerations for Australian drivers.

What is Camber?

Camber refers to the vertical tilt of a wheel in relation to the road surface when viewed from the front or rear of the vehicle. When measured in degrees, camber can be either positive or negative, each serving different purposes and affecting vehicle behaviour in distinct ways.

Positive Camber Explained

Positive camber occurs when the top of the wheel tilts outward, away from the vehicle. Imagine looking at your car from the front – if the tops of the wheels lean away from the centre of the car, that’s positive camber.

Advantages of Positive Camber:

• Reduces rolling resistance
• Improves straight-line stability
• Benefits heavy vehicles and agricultural equipment
• Helps maintain even tyre wear in certain applications

Common Applications:

• Heavy trucks and commercial vehicles
• Agricultural machinery
• Vintage cars
• Vehicles designed for rough terrain

Negative Camber Explained

Negative camber is when the top of the wheel tilts inward, toward the vehicle. This is the stance commonly seen on performance and modified vehicles, where the tops of the wheels appear to lean into the car.

Advantages of Negative Camber:

• Improved cornering grip
• Better handling during aggressive driving
• Enhanced turn-in response
• Increased lateral force capability

Common Applications:

• Sports cars
• Race cars
• Performance-oriented vehicles
• Modified street cars

Effects on Vehicle Dynamics

Tyre Wear

• Positive camber typically causes wear on the tyre’s outer edge
• Negative camber leads to increased wear on the inner edge
• Excessive camber in either direction can result in uneven and premature tyre wear

Handling Characteristics

• Positive camber can improve stability on rough surfaces
• Negative camber enhances cornering performance
• Excessive camber of either type can reduce straight-line stability

Race Car vs Road Car

In racing cars, camber settings vary significantly based on several factors.

Road Cars:

• Typically have -0.5° to -1.5° of negative camber from the factory
• Front wheels often have slightly more negative camber than rear
• Settings prioritize tyre longevity and everyday driveability

Racing Cars vary by type:

• Formula 1: Often runs -3° to -4° front, -1.5° to -2° rear
• GT3 race cars: Usually -3° to -3.5° front, -2° to -2.5° rear
• Touring cars: Typically -2.5° to -3.5° front, -1.5° to -2.5° rear, although it can be up to -6° (e.g. V8 Supercars will run -5.5 on the front and -2 on the rear).

Actual settings depend on:

1. Track layout (more twisty tracks often use more negative camber)
2. Tyre compound and construction
3. Track temperature and conditions
4. Vehicle weight and downforce levels
5. Whether it’s a qualifying or race setup

Racing teams also adjust camber throughout a race weekend based on:

• Tyre wear patterns
• Driver feedback
• Track evolution
• Weather changes
• Telemetry data

Keep in mind race cars can run these extreme settings because they:

• Have specially designed suspension geometries
• Use racing tyres designed for high camber angles
• Get regular tyre changes
• Don’t need to worry about everyday driveability or tyre longevity.

Legal Status in Australia

In Australia, wheel camber is regulated under Vehicle Standards Bulletin 14 (VSB 14) and state-specific regulations. The vehicle must maintain stability and handling characteristics within safe parameters

Important Considerations for Australian Drivers:

1. Regular wheel alignment checks are mandatory for roadworthy certificates
2. Modifications must be documented and approved by qualified engineers
3. Insurance may be affected by non-compliant modifications
4. State authorities can issue defect notices for excessive camber.

Finding the Right Balance

The ideal camber setting depends on several factors:

• Vehicle type and intended use
• Driving style and conditions
• Tire type and size
• Suspension setup
• Legal requirements

For most daily drivers, maintaining factory camber specifications or slight negative camber within legal limits provides the best balance of performance, tyre wear, and safety.

Conclusion

While negative camber has become popular in automotive culture, it’s crucial to maintain compliance with Australian regulations. Whether choosing positive or negative camber, the key is finding the right balance between performance, safety, and legality. Always consult professional mechanics and qualified engineers when making suspension modifications to ensure your vehicle remains safe and road-legal.