Sunday, March 18, 2012

FAQ for Buying Automotive GPS

Auto GPS buyers guide

If you aren’t a hobbyist in the GPS field, then the sheer number of options for purchasing an automotive GPS unit can be quite daunting. The alphabet and number soup at the end of the twenty billion models with the same (or similar) name can be incredibly confusing and unless you know exactly what you want, some of the charts and guides we have aren’t going to be much help.

So, for those of you looking to buy your first (or just a new) GPS unit, I am going to break things down a little bit. Here are a few common questions (and answers!) consumers have when considering which units to purchase:

How much should I expect to spend on a unit?

If you’ve never bought a GPS unit before, this is probably the first question you’re wondering. And, ironically, it’s one of the harder questions, especially if you’re new to the world of GPS.

The short answer is that for a basic, all-around unit with some features (but not all the bells and whistles), you should probably expect to spend $200 – $300.

The long answer is that it depends on what features you need, what features you want and how you’re going to use it. You can find GPS units anywhere from $75 – $600, but for the most part you’re going to get what you pay for. If you intend to use it on road trips with friends (who can help read the small unit), or as a GPS backup for an actual a map and directions, then one of the cheaper $100 units with few features and a small display would work just fine. If you intend to do cross-country trips solo for business, then a nicer unit with voice guidance and traffic alerts is probably warranted, and you’ll expect to spend $300 – $500.

Sometimes you can find older units on Amazon that are still good, but simply discontinued and therefore cheaper. The trick is to know what you’re getting in to. Buying a cheap unit on Amazon isn’t going to be useful if they stopped updating it four years ago and the maps aren’t accurate anymore.

What key features do I need to look for?

The list of options for GPS units is extensive–everything from live traffic updates to searching phone books and detecting weather. While all of the extra features are cool, they aren’t strictly necessary and aren’t going to be useful for everyone. Here are a few of the best features you should look for when buying a unit:

  • Advanced Voice Guidance – Most GPS units have some form of voice guidance, where the until will tell you in a flat voice to “turn left in 500 feet.” But, really, who knows how far 500 feet is? Units with advanced voice guidance (sometimes called RealDirections or RealVoice) are a little more helpful and will use street names or landmarks to tell you where to turn.
  • Lifetime Map Updates – Surprisingly, not all units come with lifetime maps, which means that you have to purchase maps every year. In the U.S., roads change an average of 40% each year (with road closings, road work and additions) so being able to update frequently is a must. After all, your directions are only going to be as good as your maps.
  • POI Search – POI stands for “Point of Interest.” This is basically a database of locations and addresses, so you can type in ‘Walmart’ and be directed to the nearest one instead of having to look up the address elsewhere and type it in manually. This isn’t actually essential, but it is very nice when exploring a new place and I recommend it. Make sure to read the specifics for this feature though, as sometimes this will require a net connection to access the database. Many times, units will come pre-loaded with POIs, but being able to save your favorites is a huge plus too.
  • Save Routes/Locations – This is especially useful if you are going to be going to and from the same places during a trip and will prevent you from having to memorize the address of your hotel or wherever.
  • Efficient Routes – So, this sounds like a ‘duh’ sort of feature, but I’m listing it anyway. Make sure that your unit will be able to list more than one route, so if you don’t want to drive over the freeway, you don’t have to. Most units have auto reroute as well, so I have not listed it, but that is also essential.
  • Lane Guidance – Whether an illustration or an actual photo of the lane junctions, this feature will help you know which lane to be in when driving through cities. Believe me, you’ll want this feature if you intend to drive through any major cities.
  • Data Cards – Make sure it has an SD card slot of some sort because more memory is never a bad thing and it means you won’t have to constantly be changing out maps.
  • 3D City View – This is necessary if you aren’t that good with a map, as it will show you a street-level illustration with arrows pointing left and right, etc, when you need to turn. If you are comfortable with reading a map, then this is definitely not a necessity.

The other features, like lifetime live traffic, voice activated directions and pedestrian navigation are nice, but might not be necessary for everyone. Of course, if you can find a unit with those features in your price range, I say go for it. These are just the things I highly recommend to get the most use out of your GPS device.

What do the letters/numbers at the end of GPS units names mean?

The letters you find at the end of those GPS unit names aren’t random–they are basically a kind of shorthand designed to help buyers sort units based on their needs.

LM – This unit comes with free lifetime map updates. Generally, that means the life of the device–generally several years. Some companies limit updates to 4 times a year or some such. I highly recommend getting something with lifetime maps. After all, your GPS isn’t going to be any help without an accurate map.

LT –  This means that the device comes with free lifetime traffic updates. This may include actual traffic, red light camera warnings, detour information, road work/road condition updates and other things, depending on the device. A lot of times, traffic will require some sort of data connection, usually through a phone, so be sure to read the details on the traffic section.

LMT – The device has both free lifetime maps and free lifetime traffic updates.

HD – The device has a high resolution display, so it will look sharper and be easier to read. On Garmin units, the HD means that the unit gets real-time traffic updates via HD radio.

The numbers, on the other hand, reflect the model number and some other information, like the size of the screen and other features. Garmin representatives I spoke with said they didn’t have a list explaining all of the numbers, as it was different for each series.

However, with four-digit models, generally the first number will be the series and the second will be the size of the screen (anywhere from 4-7 inches). The other numbers are anyone’s guess.

Does size matter?

Yes, it does.

GPS units generally come in three sizes — 4 – 5 inches, 5 – 6 inches, and 7 inches. While it might seem like the largest GPS unit is inherently better, this isn’t always the case. If you have a small car, for example, then a 7 inch would be way too large and would take up more windshield space than is really safe. On the other hand, some of the smallest 4 inch screens can be a little hard to read mounted in a large vehicle, which is also unsafe. What I recommend is cutting out a piece of paper an inch larger than the size you want to buy (to account for the mount and the sides) and then, as dumb as it sounds, go sit in your car and hold it up (or have a friend do so ) where you intend to mount the device. You might be surprised how much (or little) space the units can cover.

What are the laws for mounting GPS?

If this is your first auto GPS unit, then you might be surprised to know that many states have specific laws about where you can and cannot mount a GPS unit in your car. Over half of the U.S. has made windshield mounts illegal, so if you are going cross-country I suggest getting some sort of dashboard mount. If you really only drive in one or two states, you can check what laws apply to your state here.

How do I decide between two similar units?

When you look at GPS units from major retailers (like Garmin or TomTom) a lot of times the units will seem like they’re pretty  much exactly the same, but priced and named slightly differently. When this happens, the best thing is to pull up both units in separate pages, go to the specs section and just scroll down to see what the more expensive unit has that the other one does not. It can be time-consuming, but sometimes you can get really cool extra features for only a little bit more. Many times, especially with Garmin, the price difference will only be due to one or maybe two features so going through systematically and deciding if you REALLY need that extra feature can save you money.

If you’re looking at buying from a third-party retailer like Amazon (who tends to not have the specifications listed in a convenient way) then I would recommend going to the maker’s website and comparing the units there—many times the larger companies will have their store laid out better because it is designed just for their products. Then, once you decide, go back to your third-party site and purchase it, because many times you can get it a little cheaper that way.

How does GPS work anyway?

Ok, so maybe you aren’t actually wondering this one, but it’s something good to know anyway. Without going into super specifics, basically your GPS location is calculated based on signals from at least four out of the 30 GPS satellites orbiting the earth. The more satellites your unit receives signals from, the more accurate your position. That’s it! There are a lot of technicalities about how the system works, but it all starts with satellites. For this reason, when you are driving through dense forests or in the middle of the ‘urban jungle’ of buildings in large cities, sometimes the unit will be a little less accurate as it has trouble getting the signals necessary to calculate your position as fast as otherwise. This is normal, and improvements to the system are constantly being made to increase accuracy.

The GPS system most people use was created and is controlled by the U.S. military, but several other countries (like Russia and China) and the European Union have been working on their own systems as well. These systems are not currently fully-functional but are planned to be completed in the next few years. GPS is provided free to the public.

What other questions do you have?

Now it’s my turn to ask you! What other questions about purchasing a GPS unit do you have? Is there something you’ve never understood about GPS that you’d like me to explain? Ask in the comments below, and I’ll do my best to help you out, and might even include it in the article for others new to the world of GPS navigation!


  1. Peter Kolbus says:

    Great article, but one correction. On Garmin units, the HD suffix means that the unit receives real-time digital traffic via HD Radio, which offers faster updates (typically every 30 seconds) and covers many more roads than units without HD traffic. HD units are offered in North America.

    There is a corresponding suffix, -D, for digital traffic via DAB radio. These are European models and can receive similar quality traffic updates in UK, Germany, Belgium, Netherlands, and Norway.

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