In-car satellite navigation (sat nav) is that rarest of things, technology that makes life easier. Sat nav’s uncanny ability to help you sniff out an obscure location has made it one of the hottest selling items of recent years. Competition is fierce, which means low prices, but also bewildering choice.

The latest sat navs often come laden with extras such as speed-trap locators or the ability to navigate by photos on their maps, but you don’t necessarily need the bells and whistles. Today an excellent model can be bought for £250, as this group test shows.

In most cases sat nav maps come on an SD memory card. It’s impressive to have the whole of western Europe on one card, but if you never drive beyond Dover you’ll save up to £150 by opting for UK-only mapping, and you can usually add cards with extra maps later.

Sat nav makers claim to update their maps on an annual basis, so try to check the date of the card that’s bundled. Again, you can buy new cards with more up-to-date UK maps, but it’s often more cost effective to go for a newer machine, which will also plot routes more quickly than a premium-priced sat nav from two years ago.

Our tests were conducted on a variety of roads, from motorways to country lanes, with a deliberate wrong turn to check for the speed of recalculation. To establish whether the mapping was up to date, each sat nav was taken to a former roundabout replaced by traffic lights in 2002. Ease of use was considered vital, as were concise spoken directions.

There was little between the models in terms of basic navigation to a specified location, although the Navman made a howler on the roundabout test. They all had decent intuitive software, and apart from the basic mono screen of the Smartnav were able to show maps in 2-D or 3-D, which is largely a matter of personal preference.

Apart from the Snooper and Smartnav (which isn’t a traditional sat nav, but was included because of its unique virtues) they each boast the latest SiRF-Star III antenna. This didn’t help calculate routes any better, but picked up a reliable satellite signal more quickly than older sat navs even in built-up areas.

The real differences were in the extras. All of these models showed nearby points of interest (POI), such as food or petrol, but with varying levels of detail. Some simply gave a name, and others the address and telephone number. We checked a selection that included lodging, restaurants and cash machines, to examine both the number of POI and the quality of information.

A few machines will play back MP3 music or show photos from an SD memory card but, frankly these functions are not worth paying extra for. However, some fancier sat nav features do have genuine merit. Built-in Bluetooth generally enables you to make hands-free calls with a suitable mobile phone — worth considering in light of recent legislation changes. On the Garmin, you can transfer your phone’s address book and even dial a POI directly from the touchscreen. However, as the microphone is usually built into a sat nav, use of this feature restricted flexibility in positioning the unit.

Most can also provide live traffic information. Handy if, say, the M62 is flooded. On the Garmin and Smartnav this free radio reception feature was built in, but a receiver can be added to the Navman for £69. The TomTom works with any Bluetooth mobile phone, but charges a subscription for its own traffic-alert service.

Some sat navs will warn you of nearby speed traps. This sounds a treat, but unfortunately some were not “directional”, which means you receive warnings regardless of which side of the road the trap is on, leading to a 50% false-alarm rate. Pointless.

Overall, the standard of kit was exceptional. No matter how modest or swish your tastes, there is a well-priced model to suit you. However, if you want the full gamut of sat nav features and Europe-wide maps to boot, be prepared to spend more.

BASICALLY SUPERB

Acer P630 — typically £249, or £239 from www.clove.co.uk

PC maker serves up a top-value sat nav winner

The superb P630 employs CoPilot software, which proved reassuringly accurate. The 4in touchscreen showed clear maps with tons of useful info. Routing proved consistently quick with neat illustrations of the next turn. The points of interest (POI) were tremendous in quantity and quality and the Acer has Bluetooth for hands-free phone calls, though it won’t transfer your mobile’s address book. Inputting place names was slightly slow, but while the P630 offers few frills, it excelled at the basics and also included maps of mainland Europe.

Screen 4in Traffic info No Bluetooth Yes

BIG AND CLEVER

Garmin nüvi 610T — typically £299, or £250 from www.thenavigationcompany.com

Stylish and sophisticated, but European maps are pricey

The Garmin’s friendly-looking 4.3in touchscreen made it simple to glean information at a glance. Indeed, the nüvi 610T proved straightforward: the routing (and rerouting) was swift, it warned of upcoming junctions in good time and the Bluetooth hands-free calling feature transferred a mobile phone’s address book without fuss. It also made it easier to ring any of the POI, which were the best on test. The directional speed-trap locator and free built-in traffic updates worked well. Yet despite some posh travel tools, the 610T comes with UK maps only.

Screen 4.3in Speed traps Yes (£39pa, directional) Traffic info Yes (free) Bluetooth Yes MP3/photos Yes

ONE FOR THE MONEY

TomTom One V2 — typically £180, or £154 from www.globalpositioningsystems.co.uk

Impressive stripped-down contender from sat nav champ

TomTom’s low-budget One range is aimed at drivers eager to get from A to B who aren’t fussed by fripperies. Certainly using it proved dead simple. Accurate routes appeared in seconds and reroutes were conjured up quicker than you can say “congestion charge”. The One V2 has Bluetooth but not hands-free calling, as the feature is purely for receiving TomTom’s own optional traffic updates. The POI were plentiful, despite limited details, but featured “restaurants” were largely fast-food outlets. Well priced, and European maps are only £40 more.

Screen 3.5in Traffic info Yes, via Bluetooth phone (£29pa) Speed traps No Bluetooth Yes (not hands-free calls) MP3/photos No European maps No (+£40)

MODESTLY PROUD

Navman F20 — typically £149.99, or £120 from www.woolworths.com

Glitches don’t detract from stunning value

The F20 felt well made despite its low price. The software was intuitive and, as with all Navman sat navs, specific buttons instantly found the nearest fuel or parking. Routing was particularly rapid, and cunning: a new route was plotted within 50 yards of a wrong turn. The display showed the next two turns, but incorrectly found a roundabout that vanished in 2002, and the speed-trap service was confusing. The F20 has no fancy features, but as a no-frills alternative to an atlas it’s fine value.

Screen 3.5in Speed traps Yes (£35pa, nondirectional) MP3/photos No Traffic info No (£69 one-off fee) Bluetooth No

DRIVE SMARTER

Smartnav — £499 or £649 with screen (inc installation and 1yr routing, then £10pm) from www.smartnav.com Ideal system for drivers who hate traditional sat nav The problem with sat nav is that maps age; not so with Smartnav. You press a button to connect to an operator, who pings an up-to-date route back to you as audio directions. With the optional mono touchscreen, you can store several routes. Once your route has been logged, any traffic problems are automatically phoned through, and a new route if possible. It worked flawlessly, though rerouting was slow. Ideal for high-mileage drivers who need perfect mapping or optional extras such as vehicle tracking.

Screen 2.5in (optional) Speed traps Yes (+£80pa directional) Traffic info Yes Bluetooth No

YOU CAN BE SYRIUS

Snooper Syrius – typically £299.95, or £259.95 from www.activegps.co.uk Ensures the only ticket you’ll get is for parking

The Snooper Syrius combines speed-trap location with decent sat nav. The locator proved excellent: it gave spoken warnings that included the speed limit, and these were repeated on-screen. Trap updates are free for six months and £60pa thereafter. The 4in screen also made choosing a destination easy, but with small on-screen icons a stylus would have been handy. Despite a high price tag, the Snooper lacks extras, such as Bluetooth or traffic updates. That said, it’s extremely competent.

Screen 4in Traffic info No Bluetooth No

JARGON BUSTER

Bluetooth Short-wave radio tool that enables some sat navs to work in tandem with most mobile phones

GB or UK GB is England, Wales and Scotland; UK adds NI. If Eire mapping isn’t mentioned, it’s probably not included

Live traffic alert A free RDS radio service (also called TMC) that provides live congestion alerts to certain sat navs

MP3/photo Ability to play MP3 music or display Jpeg photos stored on a sat nav. Little more than a gimmick

POI (Points of interest) Useful nearby locations plotted onto the map. Can be routed to or phoned by touching screen

Sat nav Navigation tool that locates its position by receiving signals from 24 satellites orbiting the Earth

Speed-trap locator Ability to store the locations of speed traps and warn as you approach them