Garmin's  ColorMap StreetPilot III GPS Product Review
by Joe Mehaffey
Release 5, 21 April 2003
(update information about CityNavigator ver 4.01)

StreetPilot III Kit

More StreetPilot III  Photographs

The Garmin ColorMap StreetPilot III is in Garmin's fifth generation of GPS receivers with street level mapping.  It is their first model with a) AUTOMATIC ADDRESS-TO-ADDRESS ROUTING (A2A) and VOICE COMMAND OUTPUT (VCO).   With this unit and a copy of Garmin's (NavTech derived) CityNavigator mapping program a user will have the most detailed highway and residential street level maps available for the USA today.  The USA coverage area for NavTech maps (version 4.01) is the entire USA plus a bit of Canada.   The SP-III allows a user to automatically route using both the CityNavigator maps and/or the Base Map.  Thus,  with a "routable base map",  you can automatically route from an address in New York City to San Francisco with only CityNavigator map sections for NYC and SFO loaded.  The base map will provide information (and "road lock") for all highway routing between metro areas.    SP-III is the only autorouting system that I am aware of that can do this sort of intercity routing without the need to load intermediate maps as you go from one NavTech region to another.  (There are 10 NavTech regions in the USA and Canada combined.)  Priced at about $850,  (Check Latest Prices Here.) SP-III is the lowest priced Automatic Car Navigator -and- One of the best performers.

We think the ColorMap StreetPilot III Ver. 2.10 is  a  "break-through" in portable (move from car to car easily) address-to-address automatic routing GPS car navigation systems.    It was designed  from the   ground  up    to  economically  replace    the     combination     of GPS/Laptop  Computer/Mapping Software system that many of us  use to  maneuver around  cities in the USA (SP-III CityNavigator automatic routing maps only available for the  USA, Europe and Australia as of January 2002).  SP-III  includes   a set  of  "base maps" showing all state  and  federal highways   and major  thoroughfares  in  towns and  cities throughout the USA.    In addition,    SP-III can be loaded with optional  RESIDENTIAL street level detail maps of any USA area and a variety of overseas locations including much of Europe and cities in Australia. By using map memory  cartridges uploaded with data from Garmin's CityNavigator, MetroGuide and MapSource CDROM map systems the system can economically be used over a wide geographical area.    These include:  CityNavigator (NavTech Maps, the best GPS routable maps available in areas covered),  MapSource MetroGuide (Etak Maps, good maps but not quite as up to date as NavTech and only USA version has autorouting capability within SP-III),  Roads & Recreation, USA Topo,  and WorldMap CD ROMs.  8, 16, 32, 64, and 128 megabyte memory cartridges are available.  (Our recommended minimum size is 32megs which is the size that comes bundled with the SP-III kit.  However,  the 128meg memory module comes standard with the "Deluxe" kit and we like this size even better.)  The StreetPilot III is straightforward to use but the manual leaves some gaps that can be filled by a number of tutorial videos and CDs available from GPS vendors.

NOTE: The amount of up-to-date detail on CityNavigator maps as compared to MapSource USA maps seems to depend on where you are.  See a few examples (HERE).

The CityNavigator (NavTech) map offering is necessary for the Automatic Address-to-Address routing to work to street address level.  We have reviewed the VDO Dayton,  and the Datus RouteFinder A2A/VCO systems previously and have used the Magellan 750Nav units.  The SP-III provides automated guidance on a par with any of these and in fact much more routinely gives routing "the same as I would have chosen".  Sometimes the route chosen is "just OK",  but after all,  SP-III is just a machine.  The downside for SP-III as compared to the $3000 models is that most of the more expensive models have some sort of "dead reckoning" capability to permit navigation to continue for short intervals when signals are lost.  Such signal loss can happen in "city canyons" such as NYC and LA where high rise buildings can block the satellite signals.

As to CityNavigator map sizes,  the four central Atlanta "map chunks" are about 1.5 megabytes each,  and other area "map chunks" range from 400 kbytes to 2.0 mbytes.  To see EXACTLY what CityNavigator maps look like for YOUR area,  click HERE and select CityNavigator on the map viewer.  Keep clicking on the map until you get your area in whatever detail you want.   You can route to covered highway intersections just using the basemap.

Automatic ROUTE GENERATION with SP is pretty fast.  It usually takes less than a minute to generate a route within the Atlanta area.  One trial route from Atlanta to an address in Los Angeles took about  2 minutes which seems quite satisfactory.

CityNavigator and MapSource 4.xx offer the user a new (for Garmin) capability of generating a route automatically ON THE PC as well as within the SP-III.   This permits users to generate a series of automatically generated routes and load these into other Garmin GPS receivers as well as the SP-III.     The CityNavigator (NavTech) maps offer coverage of the covered USA Metro Areas with superior road detail.  Details as to which lane to be in and which way to turn onto exit ramps at complex expressway interchanges is included.  It is still not possible to track your progress using NMEA output via MapSource as you can using StreetAtlas 8/9/2003 and similar programs.

While CityNavigator has "city area map chunks" ranging from about 23kbytes to 2 mbytes,    MetroGuide II also has max 2 MB "chunks" (compared to the older MetroGuide version with 8MB max chunks) whereas the Roads & Recreation Maps typically load "county size hunks" which typically use 100K to 400K bytes of memory per county.  In the Atlanta area,  the coverage area  for a selected 8 MB MetroGuide or CityNavigator map section is roughly  a  square about  125  miles  on a side.  This covers  the  formal  "Atlanta Metropolitan Area" and then some.  Using the less accurate (but still very good) MapSource R&R maps,  you are able to include a much larger area and up to 99 "counties" in an 8 meg memory cartridge.  (See the MapSource Product Information for more detail.)  Note:  As of this date,  NO OTHER map products (from alternative vendors) can be uploaded into Garmin GPS receivers except those offered by Garmin for the purpose.  This same proprietary relationship exists for other vendor's consumer GPS products as well.  The 128Meg map cartridge will typically cover two or more states but this varies with road density within a state.

This new SP-III is designed principally for automobile use and its size,  the two hour (or so) battery life and lack of off road features make it unsuitable for hiking or boating use.  NiMH rechargeable batteries give better service than alkaline.

What's new in StreetPilot III?

The SP-III DELUXE kit contains: SP-III GPS, 128meg memory,  Speaker/power cable,  USB memory loader,  Dash Mount Bracket,  CityNavigator CDROM,  Manual, and a data cable for computer interconnect.

We can say that SP-III gets rid of almost ALL of the  error effects of GPS error  that bothers so many people.   When you use CityNavigator or MetroGuide the SP-III will  "lock" your vehicle track to roads and as long  as you   travel  on  the  road.    (This feature does not operate with MapSource R&R, USA Topo, or WorldMap.)  Automatically generated routes using CityNavigator maps "rubber band" to the roads in the route.  Once in a great while,  you may find an isolated road segment where the map is so far off that road lock will jump off the road,  but it is extremely rare.

Another useful feature is that with CityNavigator (and MetroGuide) maps, (when not in guidance mode) all approaching cross street names are displayed prior to arrival.  We found the SP-III audio and visual  guidance directions  very  satisfactory.  SP-III  automatically varies its "turn here" warning time  to give you  more warning time at high speed than at lower speed.  A typical audio/visual sequence would go something like this:

At all times,  the map on the left half of the screen shows your progress and a thick pink line shows your project route on the map.  On the right is the text information: speed,  time to go to next turn,  distance to go to next turn and written directions/information as needed.  At any time,  you can press the "speak" key and get the latest directions in audio form.

An alternative screen shows a listing of turns to come.  Another screen display is the trip computer.

AUTOZOOM  zooms  the  screen in and  out  automatically  as  you approach  waypoints  and turns so you always have  time  to make decisions.

Route selections for CAR, TRUCK, BUS, and EMERGENCY are provided so you can be properly routed depending on your vehicle type.

The  accessory CityNavigator and MetroGuide Maps contain many thousands   of "attractions"  on  board.   These include:
Food and drink,  Lodging,  Attractions,  Entertainment,  Shopping,  Services,  Transportation,  and  Emergency and Government.  In  our  area,   there  were a few restaurants we had  not  known about (and  a   few   prominent ones   are  missing).   The restaurant listing appeared to be about 2 years old.   Listed  "Attractions"  include theme parks,  museums,  libraries,  schools,  parks and such.   The  listings  were  quite satisfactory though  the  placement of a particular restaurant or gas   station  might  vary  plus  or  minus a few  hundred   feet (once,  half  a mile) from  the  actual  location.   This  feature could be very handy in a strange city.

The user can give the GPS a Street Address or Street Intersection or  select  one of the, for instance,  Restaurants  in  the accessory map data base module and it will LOCATE this address or location  automatically and plot it on the map screen.   The  SP-III can then automatically create a "turn-by-turn" route to this destination from wherever you are.  This is a very useful feature and it has worked very well in our tests.  Be prepared for a few well known items (such as my local library) to be missing from the "attractions" list.  Still,  if you are unfamiliar with an area,  what IS included will be quite useful.

Are 128 megabytes of MAP MEMORY enough?

We think the 128 megs is enough for "most" users.  SP-III  has a map memory of 128megs available and also a "complete USA basemap".  The basemap has the entire USA included as far as major roadways,  state numbered roads and interstate highways are concerned. 

Then,  if you need complete detail for a PARTICULAR city (or rural area) you are going to visit,  you can load (from your laptop or other IBM type Personal Computer) high detail maps from CityNavigator. 

So..  If you are going from (say) Chicago to San Franscisco and back to Miami with a stop in Denver,  you would load detailed maps for the four urban areas of interest and let the basemap be your guide for other areas and still have lots of empty memory in your user map cartridge for other areas.  The unit automatically transitions from the basemap to the detailed maps when the detailed maps are available and back again as you move out of the detailed map areas.  While it is quite easy to load new maps from a laptop computer into your SP-III,  you could just have multiple map cartridges and plug in a new (preloaded with maps) cartridge for various areas if you did not have ready access to a computer on a lengthy road trip. 

SP-III does not have the 2Gigabyte map memory we all wish for, but it is quite flexible and the basemap goes a long way toward making 128megs of map memory sufficient for most users.  That said,  DO NOT expect that the basemap is as accurate as the CityNavigator maps from NavTech.  There will be some areas where the map error is larger than 150ft and the SP-III will think you are offroute and will claim it must recalculate.  This is a minor irratation for some people but if you just ignore the problem when it (fairly rarely) occurs,  things work out fine.

What are the Technical Specifications of the SP-III?

Specific Questions Answered:

StreetPilot Feature and Function Highlights

We do not recommend SP for hiking or marine activities due to its reduced feature set optimized for automobile use.

The  SP-III Prototype used for this review includes no basemaps outside the Western Hemisphere.  I believe the production unit will have a rudimentary base map for the world.  More on this later.  The basemap has less detail in South America and no railroads,  but  more  roads  in  Canada  and  Mexico.  The basemap of the USA includes maps  of USA interstate,   national,  primary and  secondary  state  highways,  cities, larger towns,  waterways, rivers, and coastlines.     (Note:  See  Garmin Base Maps description for  more  information  on Base Map  content.)   Base Maps  are included   in the SP-III's  internal memory while USER Uploadable Street Maps on CD ROM provide  street level or topo detail of user selected  areas  which are loaded to the 32 meg  or 64 or 128 meg memory cartridges.  (Note:  older 8 meg and 16 meg cartridges can also be used with SP-III.)

Additional SP features include:

The trip computer is improved and has functionality similar to the SP(CM).  With SP-III,  You will notice that when you come to a stop, the  estimated times  do  not go to infinity,  but hold a  realistic  value.  The GPS calculates estimated times based upon road classes in your  Route and  modify the estimation by your actual speeds on  the  various road  classes. It also computes the actual road distance  between turns (waypoints) instead of using straight line distances.   The results  give fairly accurate estimated time to  various  points,  even  when  using different road classes, like traveling  on  the freeway,  and  then  exiting  later on  some  local  roads.  Your estimates will not only be based upon your current highway speed,  but by the combination of speeds you are using, or will be  using on the various road classes.

The  GPS  has the standard HOST mode  which  allows   the upload/download of waypoints, routes,  tracks,  etc.,  OR use the GPS for tracking with the NMEA output WITHOUT having to change from GARMIN to NMEA  mode  and vice versa.  The SP external power/data cable and active antenna BNC  connection is the same  as for the G-III(+) and G-II(+) and earlier SPs..

Note:  None  of the  "display fields" are user configurable in SP-III.  A "satellite"  page (menu/menu+GPS INFO)  rounds out the  active displays.  Another display shows loaded maps and allows user selection of "active" maps.   If you have multiple maps of the same area (a TOPO and CityNavigator for instance) you will want to turn off one or the other and use one at a time.

MetroGuide's Find-an-Address feature includes: Intersection, Place, Restaurant, Hotel, Entertainment capability.  SP (CM) can find  such places   in  the  upload coverage area.  Even a restaurant less  than one  year   old   were  included.  However,   some   of   the locations   of  restaurants, hotels,  etc.  are  misplaced  by considerable distances.

A  "Driving Status"  line  on the  Map  display  indicates such information   as  "Driving  South  on  Roswell   Road   near Sandy Springs".   This  can be quite useful in cities  where you  don't exactly know which street you are on.  Also while driving, the name of each approaching side street is displayed allowing finding side streets in the dark.

Major features the StreetPilot DOES NOT have compared with G-III+

Datums-  The SP  only  provides  WGS-84  so any  external mapping program which cannot  use  WGS-84 directly  OR convert  WGS-84 to its  required  datum will give  larger  than  normal map position errors.

Battery timer- The SP has no battery timer feature.  It does have a  battery "fuel gauge" display and MORE IMPORTANT,  SP-III has an "Automatic Shutdown when External Power is Removed" feature to prevent running down the internal batteries if you forget to turn off StreetPilot in your car.  Unfortunately,  it does NOT have automatic power ON when external power is applied like other Car Navigation systems.

43  ICONS are available in the SP-III to identify  user  waypoints and  mark  routes.      The battery meter can  be set to alkaline, or NiCad types.   Alkaline battery  life in the SP (6 AA cells) is about 2  hours.

Street pricing of the SP-III is about US $850 or less and includes: 32 meg memory cartridge,  speaker/power cable CityNavigator CDROM and a password key for one (of 10) USA/Canada regions.

Features and Operation

The SP-III has a direct and easy to use routing system.  The user:

The SP-III has essentially NO CAPABILITY for off road guidance.  It is not suitable for Marine or Hiking use.  (You can do a GOTO if you select OFF ROAD as your routing preference.)

 The SP-III operates from 6 AA batteries or from external power in the range  of 10 to 32 volts DC.  The SP-III uses FLASH memory and has no memory backup battery.  We get about 2 hours from a  set of 6 Toshiba/Sony Alkaline AA cells.   Best to keep the unit plugged into external power.  The LED  backlit display  lighting has a rated design life of 100,000 hours.   The SP shuts down when the internal battery voltage  goes  below  4.8 (alkaline) or 5.2 (NiCad) volts unless external power is applied.

A special Power/Speaker cable is supplied with SP-III.  However,  the   data/power  cable  used  is  the  same  as  the  Garmin  G-45/12/II+/G-III+ and other SP units.  Normally,  you would not need a DATA cable if you use the USB module to load maps into your SP-III.  However,  you will need a data cable if you intend to upload/download routes/tracks/waypoints directly to MapSource or to other 3rd Party Software.

The external antenna connector,  a BNC  coax jack,   is located on the right rear of the unit just behind  the keys.   The BNC jack is powered and has a current limit rated  at 50 ma    to  protect the unit from shorts on  the  antenna  cable.  However,   the standard antenna is passive.     The Garmin GA-26  amplified antenna, Lowe's,  Tri-M,  and the MAGELLAN M-4000  amplified  antenna all work  with the SP.   We believe most  other  amplified  GPS antennas will work as well.

The  SP-III outputs out only the NMEA protocol NMEA-0183  ver  2.0  and accepts  RTCM-0104.  Other proprietary GARMIN sentences  are input/output  as well.   Garmin has included its (now) standard HOST MODE  (Called  GARMIN  in the GPS)  so  that  (with suitable  software  commands) it is now possible to  switch  from NMEA  to up/download without manual intervention.  The   NMEA out, TEXT out, DGPS in, and RTCM in are also available.

DGPS  signals in the RTCM-0104 format are accepted.  Anytime  NMEA output  is selected,  the baud rate of  the output serial port is set to 4800 baud and input is disabled or it can be set for RTCM in and NMEA out.  RTCM (DGPS) alone can use  baud rates  of 300 to 9600.  A setup screen permits selection  of  the I/O combination needed by a particular application.

Operating temperature range is specified as -15C to +70C.  Unique in  their  class,   Like other Garmin handheld GPS receivers,  SP is rated submersible to one meter per IEC529 IPX(7).  The maximum altitude rating is 60,000ft and speed maximum is 999 knots.

Master Reset:
Hold down the quit button, route button, and up on the rocker pad. Press power button, wait until you get the first
power-up screen then let go of the up and wait for the unit to come on fully then let go of the rest of the buttons.

Feature Details:

  • The  SP-III  has a large  number of features and displays.  These include:
  • Subjective Observations of Performance

    I  have tested the SP on the roads and  highways of  North  Georgia  including several interstate trips.   Our  SP  has worked  properly at all times as far as we could tell.  We  tried uploading   and   downloading  waypoints,   tracks   and   routes using  G7ToWin.   We tried it  out  on SA5, 6, and 7,   Precision  Mapping  3,  Vista,   AutoRoute  5.   Generally tracking  worked well,  and SA7 upload/download functions  worked OK.    (However,  most  upload/download programs   will  require later   releases  for  all   of   the   new   SP  functions    to upload/download properly.  Examples: 50 icons,  One 10  character names,   commands  to use Garmin's  new  "no   touch"  switch over from  NMEA  to UPLOAD/DOWNLOAD.   All map programs  tested  which specified  a   NMEA-0183  ver 2.0 data stream  as  input  tracked properly with the SP.

    We compared the SP with the G-12XL, G-III+, G-II+ and the EEx2.   The SP  performed  on  a par with all units in every  test  for  lock stability,   multipath performance,  re-lock after an  underpass,  and  ability to suddenly change direction without loss  of  lock.  The  SP  laid down smooth tracks on our highway maps  during  all tests.   No gaps,  jumps,  etc., (The SP has data smoothing  like the G-III+.)

    We  noted that all SP models and G-III+ (along with the G-12XL and  the G-II+)  have a form of "dead reckoning" for moments  when  signal dropouts  occur.  For instance,  if the SP-III is tracking along  and just before a sharp turn you invert it and block its antenna,  it will  continue to track straight for about 30 seconds.   It  also provides  a very good data smoothing filter to throw  out  random fixes  that are way off track.  This results in an  exceptionally smooth  track on a moving map display even with the  "road  lock" option  turned  off.   Even  with  this  filter,   there  was  no overshoot apparent during quick stops,  sharp turns,  and similar maneuvers when normal continuous tracking was taking place.

    SP-III  performance under tree cover and city canyon  conditions  was about the same as the earlier SPs,  G-III+, G-II+,  G-12XL and the EEx2 and we rate that as  very good.

    We  found the display controls easy to learn and use.   The  menu system and arrangement is quite satisfactory.  (No manual was available at the time of the review so we may have missed a few features).  The SPIII has many feature  changes   as compared with the older SPs and other handheld units.  However,  after a couple of hours of operation,  we found the SP-III  menu system both adequate and easy to use.

    Since the SP-III,  SP, G-III+,  G-12XL and the G-II+  exhibited  essentially  identical  tracking  performance  in  our tests,   we  did not perform the extensive field trials  we  made with  the  G-12XL,   EE, and others.   For  more  information  on tracking  results with our testing of the G-12XL,  and the  G-II+, etc., see our reviews at:


    Our  overall  impressions  are  that the  StreetPilot  III is  a  new generation  of low cost  Automobile  Navigation Systems.  With the lowest price of any truly automatic self contained address-to-address car navigation system and the superior NavTech street maps,  we consider the SP-III to be revolutionary in its price class.  With the SP-III,  I believe we can eliminate having to use paper maps for car navigation (in the covered areas).

    What  DON'T  we  like about the  StreetPilot III?
    1)  The unit drains batteries extremely rapidly.  It will be extremely advantageous to operate it  from external power.  This problem is mitigated by the  "automatic shutdown  when   external power is removed"  feature.
    2) The CityNavigator software for "all" or one of ten regions of the USA comes bundled with SP-III depending on the kit selected.  An individual additional region cost about $99 and the bundle with "all the rest" of the USA costs about $200 or so.    Many will opt right away for the "entire USA".  This is a bit pricey for many buyers,  BUT>  it is the best car navigation map system that you can buy and Garmin's price is considerably  less than other car navigation vendors charge for the same map capability.  These are apparently the same maps that are used in the $2000/$3000 car navigation systems.
    3) The simulator is a bit hard to steer and gets off track now and then,  but this is "picky".
    4) We would like to see the SP-III power up automatically when external power is applied.
    5) On occasion,  we see the router generate "funny routes" such as taking a busy numbered federal highway instead of a nearby freeway.  All Car Navigation routers we have used seem to do this from time to time and so I guess it is "just the state of the present art".

    Which  GPS  do  I use now when I go  on  automobile  trips?   The StreetPilot III.  Would I take it hiking or boating?  No.

    If  anyone  has any additions,  questions,   suggestions,   error corrections  other comments,  please feel free to Email.

    Joe Mehaffey