Buying guide: GPS units and sat navs

Need help shopping for a GPS unit? Deciding between sat navs from Garmin, TomTom and Navman? Read our handy buying guide

FAQs: GPS units

What does GPS stand for?

GPS stands for Global Positioning System.

How does a GPS work?

More than 24 GPS satellites orbit the Earth and transmit signals. These signals allow the receiver in each GPS unit to work out your location, travelling speed, and direction. The GPS unit then combines this information with an electronic map to pinpoint your location and provide directions.

Does a GPS system need to be installed into my car?

No. Portable GPS units can be transferred from car to car using a suction cup mount that sticks to your windscreen. GPS units for cars include this mounting bracket in the pack, and you can easily set it up yourself. Some new cars come with GPS units built into the dashboard, but this is usually an optional extra.

Can I get a portable GPS system to use in several different cars?

Yes. GPS units can quickly and easily be transported from car to car. This is as easy as unclipping the unit from the window mount, and then removing the suction cup from the window. You can then take the GPS and use it in a different car.

Will my GPS work in all areas?

A GPS will work in any area that has a clear view of the sky. Most GPS units will be unable to receive a GPS signal through tunnels or underneath bridges, but should recover the signal as soon as you are back outside.

Do GPS systems provide voice directions, visual directions or both?

In-car GPS units have both voice and visual directions. Visual directions are displayed as a map on the GPS screen, while a voice will guide you to your destination by telling you where and when to turn. Most GPS units broadcast the street names audibly using technology called text-to-speech, while others simply tell you which direction to turn, and how many metres you have to travel before your next turn.

Can I use my GPS in any state or country?

You can use your GPS in any country, provided it has maps installed for that country. GPS units sold in Australia will always have maps for every Australian state and territory. Some GPS units also provide maps for other countries or continents as standard. Nearly all maps on GPS units can be upgraded, so updated Australian maps and maps for other countries can be purchased. Ideally the maps should also be updated at least once a year to ensure any changes to roads and traffic alerts are kept up-to-date. These updates incur a fee.

Does my car require an external aerial for GPS?

No. As long as the GPS has a clear view of the sky, there is no need for an external aerial. GPS units that are built into a car's dashboard require an external aerial.

Does my GPS work on batteries and how long will the batteries last?

Most GPS units use internal batteries that can't be removed. They have a plug to recharge them that can be connected to your car’s cigarette lighter so you can keep the GPS unit charged while on the road. The battery life will differ on each GPS unit, but on average, a GPS battery should last between three and five hours on a full charge.

Can you get voice-activated GPS systems?

There are a number of high-end in-car GPS units on the Australian market that have an element of voice activation, but this technology is still in its infancy. A GPS unit that can be completely activated and controlled by your voice is likely to be developed in the near future.

Join the PC World newsletter!

Error: Please check your email address.

Tags notebooksbuying guideGPSsat navmobiles phonessmartphones

Our Back to Business guide highlights the best products for you to boost your productivity at home, on the road, at the office, or in the classroom.

Keep up with the latest tech news, reviews and previews by subscribing to the Good Gear Guide newsletter.

GoodGearGuide Staff

Good Gear Guide
Show Comments

Cool Tech

Crucial Ballistix Elite 32GB Kit (4 x 8GB) DDR4-3000 UDIMM

Learn more >

Gadgets & Things

Lexar® Professional 1000x microSDHC™/microSDXC™ UHS-II cards

Learn more >

Family Friendly

Lexar® JumpDrive® S57 USB 3.0 flash drive 

Learn more >

Stocking Stuffer

Plox Star Wars Death Star Levitating Bluetooth Speaker

Learn more >

Christmas Gift Guide

Click for more ›

Most Popular Reviews

Latest News Articles


GGG Evaluation Team

Kathy Cassidy


First impression on unpacking the Q702 test unit was the solid feel and clean, minimalist styling.

Anthony Grifoni


For work use, Microsoft Word and Excel programs pre-installed on the device are adequate for preparing short documents.

Steph Mundell


The Fujitsu LifeBook UH574 allowed for great mobility without being obnoxiously heavy or clunky. Its twelve hours of battery life did not disappoint.

Andrew Mitsi


The screen was particularly good. It is bright and visible from most angles, however heat is an issue, particularly around the Windows button on the front, and on the back where the battery housing is located.

Simon Harriott


My first impression after unboxing the Q702 is that it is a nice looking unit. Styling is somewhat minimalist but very effective. The tablet part, once detached, has a nice weight, and no buttons or switches are located in awkward or intrusive positions.

Featured Content

Latest Jobs

Don’t have an account? Sign up here

Don't have an account? Sign up now

Forgot password?