Ask yourself these questions What tires are on my 4WD now? Did I like my old tires? (Smooth ride, good handling, long wearing, etc.?)

What do I want my new tires to do? How important is crisp handling and quick stopping compared to smooth ride or long wear? What kind of "look" am I after? What level of convenience, service and warranty do I expect?

When you answer these questions, you narrow the choices to ones that fit your specific needs and wants. It helps the salesperson too. He or she won't waste your time discussing tires you don't want.

Determine your size Look in your 4WD owner's manual. You'll find the size fitted on the car originally. Unless you've changed wheels, that's the original size.

• You do not have to fit the original size.  Check with your tyre dealer for recommendation on alternate sizes.

Width of the tire, in millimetres The higher the number the wider the tire. Improperly matching of wheel and tire size can cause serious injury or death during installation.

Aspect Ratio The height of the sidewall section compared to the width of the tire. Example: - If this number was a 50, then the tire section is half as tall as it is wide. Short sidewalls deliver crisp handling. Tall sidewalls give a smoother ride. For a specific tire width, the smaller this number, the shorter the sidewall.

Construction R indicates radial construction. Unless you specify the other option, bias (which would have a D [diagonal] or B [belted bias] in this position instead of an R), you are purchasing a radial tire.

Wheel Size Designation This indicates the distance across the "doughnut hole" of a tire, in simple terms. You must match wheel diameter and tire diameter. For example, a 15-inch diameter tire must only be mounted on a 15-inch diameter rim.

Service Description Includes the load index (a number) and a speed symbol (a letter). NOTE:  Load index.  If your tyre placard (which is usually fixed to the door pillar, or the inside of the glove box) does not specify an axle rating or allow a lower load index you must fit what the original index load rating is.  If your placard states an axle rating you may change from the original load rating. This means you can change the load index, as long as the load of the two tyres is greater than the highest axle rating.

The Speed Symbol It means the tire is speed rated on an indoor test wheel.  In Australia you do not have to match with the original speed rating either stated on the tyre or on the vehicle placard.

The Australian requirement for four wheel drives is a Minimum of N being 140 kph.

Where should I buy my tires? Buy your tires where you feel comfortable: a place you feel will take care of you during and after the sale. Because tires may have warranties as high as 80,000 kilometres or more, the period after the sale may be several years. Tire professionals help you maximize your investment and get the right tire for your driving needs. Buy your tires where the sales force helps you, not just sells you. In short, buy their reputation as well as their tires.

Tyres | Buying Guide | Technology | Size Guide | Speed Rating