One of the first apps I bought when I got my iPhone 4, back in the 19th Century, was CoPilot, the slightly cheaper alternative to TomTom. Both apps cost 30-something quid for the Western Europe edition, and like all proper satnav apps they allow you to navigate without needing a network connection. This is their chief advantage over the built-in Apple Maps app, or the venerable Google Maps.

For some time after Apple released Maps, I didn’t even have Google Maps on my iPhone. Both my 4 and my 5 were paltry 16GB models, and I couldn’t afford to keep stuff around that was’t paying its way in terms of storage space used. But my iPhone 6 Plus is a 64GB model, and I downloaded the Google app again recently, and started experimenting with using it as a sat nav.

Why did I feel the need? Hard to say. Nothing much wrong with CoPilot, but it does charge you a subscription fee for its fairly lacklustre traffic/rerouting feature. I had this for a couple of years (only one of which I paid for) and it never once saved me any time or got me onto another route. It would notify me of 5-10 minute delays, but it always said there was no quicker route. I’m also not enamoured with CoPilot’s Points of Interest feature. They never really are points of interest, and it’s rubbish at finding the supermarket you know you want, or the car park.

Because G Maps is connected to regular Google search, you can find just about anywhere using the words you would use. For example, CoPilot is hopeless at identifying the Eurotunnel terminal at Folkestone, whereas it pops up in G Maps immediately. In the example above, ‘Waitrose Milton Keynes’ is near-impossible to find in CoPilot, but Google gets it.

When I tried Google Maps, I was immediately impressed with the speed/accuracy of its traffic feature, which pisses all over the service offered by Apple Maps. Google’s harvesting of data is obviously on a different level.

Another thing that has impressed me about G Maps is its estimation of journey and arrival time, which has proved far more accurate than CoPilot’s. I’m a person with a great sense of direction (fact) and I generally learn how to get places when I’ve been once, so I don’t need a sat nav unless I’m going somewhere entirely new. On the other hand, when I’m on a journey of any length, I do like to know ‘how much longer?’ and to have a rough idea of what time I’ll arrive.

I confess I’ve become obsessed by this latter since starting my new job with its horrible commute. It’s not about arriving at work, but rather getting home. Anything around an hour or slightly under is a triumph. It helps too, when I’m feeling a bit frazzled and tempted to leave the motorway to take the A5 or something. When Google tells you the A5 will take 12 minutes longer, you stick with Plan A.

Google colour codes both the route and the time till you arrive. The road you’re supposed to be on is blue. Alternative routes, as they come along, are shown in grey, with an indication of how much longer or shorter they’ll be. A cross-country grey route that’s ‘1 minute longer’ is usually a good bet, if you know the blue route takes you through a town centre and a series of traffic lights at rush hour. You can usually make up the minute fairly quickly and use less fuel on a more direct route on country roads.

When there’s slow moving traffic, the route turns orange. When the traffic is stationary, it turns red. As to the time indicator, it’s green when you’re on target to hit Google’s original prediction (or go slightly under). It turns orange when there’s a slight increase, and red when you’re going to face considerable delay. Interestingly, it also turns black when the arrival time gets ‘locked in’ by the laws of physics. If you’re two minutes from home you can no longer make up any time.

Google’s orange-red coding of the route is not exact, but it is pretty good. When the motorway matrix signs are saying ‘Queue After Junction’ you will see the red or orange ahead. On the A422 towards Buckingham, there’s often a patch of orange at the Maids Moreton right turn, because this frequently causes a shift into first gear and a short delay. What’s good about this is that it reminds you, sometimes, not to go hurtling round a corner at top speed, because there’s orange ahead.

What I really like about G Maps is the usual offering of 3 alternative routes, with live traffic information. Even then, you still have the option of cutting onto a back road, and instead of insisting that you ‘turn around when possible’ G Maps takes it in its stride, and simply recalculates the route and arrival time. It’s also very smart when it comes to map display. You can see it zoom in as you get to a junction, and it then zooms out again to show you more of your route. This is much more flexible than CoPilot’s display, which is something you have to adjust yourself.

The one drawback is that G Maps needs a data connection and uses quite a lot of data. I’m on an unlimited plan. Still, when I drive in France, I would normally revert to CoPilot, because the maps are already downloaded. Except now France is a Feel at Home destination on the Three network, which means I can use my existing data plan (within reason) when I go. When you’re in an area with no signal, G Maps can get very flaky. It’s not good at  calculating a route on the move, and I did experience a number of app crashes when driving in France at half term. The app has been updated more recently, and hasn’t crashed since the update. It still prefers you to be stationary when it’s calculating a route, though.

The thing I miss in G Maps compared to CoPilot is the display of the speed limit wherever you are and the GPS-calculated speed you’re doing. Surely it would be possible for G Maps to display this?

As to Apple Maps, its key advantage is the way it carries on working in the background, even with your phone screen off. I quite like the way it wakes itself to display the map on the lock screen as you approach a junction. On the other hand, when you’re driving somewhere like Milton Keynes, it gets irritating to hear ‘take the second exit at the roundabout’ 50,000 times. Google Maps has a less irritating voice, which is easy to mute and unmute, depending on your circumstances.

Short version: if you have a decent data plan, the free Google Maps is all the sat nav you’ll ever need.