Car Handling Basics


April 11, 2013 By Mike Lee
Last updated on July 27, 2015

There are many aspects to your cars handling ability, and depending on your cars layout, structure and type they will all have different characteristics.

In this car handling basics article we will discuss the various conditions and properties that affect your cars handling characteristics.

Understeer
The front wheels of an under steering car tend to slip a little and drift towards the outside of a turn. Many cars (mostly FWD) tend to have a little under steer built into them from the manufacturers, as it is seen to be a safer option than over steer for the average motorist.

Oversteer
The rear wheels of an over steering car tend to slip a little towards the outside of a turn. The driver must correct this by steering away from the corner, otherwise the car is liable to spin if pushed to its limit. Over steer is sometimes useful for the experienced driver, who can manipulate the over steer with the power of a rear wheel drive or even 4wd car, while cornering.

Oversteer and Understeer on the track

Bumpsteer
This is caused by the affect of the cars suspension on the road surface. Quite often the suspension may not be moving quickly enough in an upward or downward motion to make contact between the road wheels and the road surfaces. The wheels will therefore leave the road surface and therefore alter their yaw angle, causing bump-steer.

Weight Distribution And Transfer
Your cars handling will be affected by the cars weight distribution and the way that weight is transferred under braking or while cornering and even when accelerating. As you corner, your cars weight is transferred to the outside suspension/wheels/tyres causing the car to roll, if you also apply braking into a corner you will also be applying a greater amount of that load to the front outside corner of your cars suspension/wheel/tyre (more about how to drive effectively in another article). Some cars will tend to under steer and others will tend to over steer. Rear wheel drive cars tend to over steer and front wheel drive cars tend to under steer. All this is amplified by the amount of weight above your cars centre of gravity and the amount of roll your car has (lack of stiffness in the suspension).

If you intend to do any spirited cornering (on a track), we would suggest you learn about your cars characteristics and how to make alterations when certain conditions arise.

Carrying on from above, if you intend to go racing or just want more out of your car in terms of your handling and performance, you can further reduce the weight being transferred and shifted about, by adding light alloys, lighter/or removed bumpers and replacing panels, doors, wings, bonnet, boot etc with fibreglass replacements. Apart from the reduced amount of weight being transferred under braking, acceleration and cornering, the car will benefit from an increase in power to weight ratio.

  • Track: The wider the track (distance from one wheel to the other wheel width ways) the less sideways weight transfer and body lean there will be.
  • Wheelbase: The longer the wheelbase (distance from one wheel to the other wheel length ways) the less weight transfer to the front there is under braking.

Affect Of The Centre Of Gravity
By lowering your cars centre of gravity, you can improve your cars handling. Apart from suspension mods, there are other things that can be done to help, although how far you go depends on what your car is going to be used for. Using plastic windows, a plastic or fibreglass roof, bonnet and boot will reduce the centre of gravity.

Driven Wheels
The driven wheels can have an affect on your car handling. A rear wheel drive car will tend to over steer, while front wheel and 4 wheel drive cars tend to under steer.

Power Through The Wheels
It is possible (for the experienced driver) to control a car using the power of a rear wheel drive car. This has become popular with the drifting crowd. By using the power to create over steer a skilled driver can manipulate the cars cornering abilities.

Steering Response
Your cars steering mechanism and response can affect your cars handling, there are some aftermarket steering improvement components available for some cars. Mechanically the rack and pinion steering system is pretty good. Some cars also have a 4 wheel steering system – Honda Prelude, Mitsubishi 3000GTO, Nissan Skyline (option), but this has become less popular with the manufacturers nowadays.

Aerodynamics
Can have an effect on your handling, in as much as the more down force you have at higher speeds, the more stable your car will be. Down force will improve your cars suspension work and create more positive contact for your cars tyres, creating increased adhesion. Adding a rear spoiler can increase rear down force at higher speeds depending on the car (more comments on aerodynamics in the accessories/body kit section).

Other Basic factors that will affect your handling are

  • The tyre condition or type of tyre used
  • Your wheel choice (diameter, width, offset)
  • Incorrect wheel alignment/geometry
  • The weather condition (rain, ice and snow)
  • Road condition (as above, plus oil and uneven surfaces)
  • And of course your driving skill

Millbrook Proving Ground

Please now see our articles on:
suspension and chassis, brakes, wheels and tyres.