It depends how busy your phone is. If you get lots of messages, emails etc they get in the way of the satnav instructions.

I use Sygic on the phone. Basic version is free and no data used, but no turn by turn instructions and it reminds you constantly with a spoken advert to get premium for turn by turn.

However I also have a standalone which I use for longer trips.

I know people with unlimited data use google maps for instructions on their phone, i don't do that i just click on maps and use it for checking traffic often.

I have a professional company supplied Garmin system in the lorry, and also a Garmin standard satnav for the car, in both cases only used for directions once in a blue moon, but the one in the lorry is in use continually for traffic.

And there is the difference, the one in the lorry has digi traffic, and if you are going to buy a stand alone i suggest making sure it comes with digi (not standard or any other kind of) traffic, which is free for life, no its not as good as Google maps traffic or Waze,assuming you can make head or tail of Waze, i can't.

Some satnavs that come with traffic are still using your phone data to link up, and some others (ie TT) there is an annual charge to pay for traffic, haven't a clue about this because i can't get in with TT's at all anyway.

For my regular use of google maps i never get anywhere near using up my 5g of data, whatever 5g might mean, but if you only use the thing once in a while for satnav purposes maybe it would be worth increasing your data package for your phone anyway and cost effective, there is no doubt that Google maps traffic will make all of your journeys more pleasant with there being very little chance of encountering surprise traffic en route, the difference this makes even on my work commute is amazing, almost never get caught out now, fort either type i prefer not to have a destination entered and just put an overview up so i can keep and eye on the changing traffic situation, like you seldom need directions as such.

20Mb per 20 mins spund like a lot of data to me, especially over a longer lourney of 5 hrs plus. I found that using a dedidcated satnav app with maps downloaded via wifi and only traffic levels and incidents gives the best combination of low cost and decent usage.

I have been using HERE Drive on my Nokia 620 Windows phone (as it was free as part of the original phone cost), but now that Microsoft don't include the live traffic updates any more, it's only useful as a mapreader app if your are driving on your own.

One other problem that using mobile phones have is that they are power hungry and thus need plugging into your car (via a USB socket or cigar lighter adapter) to use, especially on longer trips so you have a decent amount of charge left to use the phone. The cables can get in the way a bit.

Now my phone is essentially obsolete because the OS has no useful apps or compatability with most provided by banks, satnav providers, etc, I'm forced to choose whether I spend at least around £120 for another phone (the phone part of my one works fine for the most part) with Android and have to pay more for the extra bandwith to cope with Google Maps over standard satnav apps or buy an app and annual updates, or keep my phone and spend about £60 - £80 for a decent satnav unit with lifetime map updates, assuming it can be used with my phone to receive the traffic reports.

I think this often ties in with what you use your mobile phone for and the level of downloads (i.e. tarriff level) you need per month.

I use Waze mostly and sometimes Google maps. Waze is usually preferable as Googlemaps tends to shut down unexpectedly if the phone is touched.

I use Waze mostly and sometimes Google maps. Waze is usually preferable as Googlemaps tends to shut down unexpectedly if the phone is touched.

In the car I won't use satnav on the phone because the law will award me with a big fine and points if I so much as touch the handset whilst in the driver's seat ... unlike a built in satnav or freestanding unit.

I don't believe that is true - you can use it as long as it's in a holder/cradle rather than being held.

The standalone satnavs are better, particularly the higher end ones with proper traffic. They are purpose designed and are just slicker to use.

However, nav on phones these days is very, very good and even just good old free Google Maps in Nav mode is really pretty solid.

So, if you occasionally need Satnav just get yourself a cradle to hold it in and some sort of power cord and it'll probably be all you ever need.

Google Maps doesn't use much data and let's be honest most people never use whatever data they are paying for and it's pretty cheap. Can't see it's an issue personally.