WAAS made a lot more sense before the SiRF III chipset, when GPS receivers were much less sensitive/accurate. With SiRF III, WAAS is a waste of time since the SiRF III is much more sensitive and accurate than WAAS. You save power consumption when you don't use the WAAS feature while on battery mode, so now it makes sense why Garmin ships the unit with WAAS mode disabled.

What doesn't make sense is why Garmin even includes WAAS, since the on-board SiRF receiver is better than WAAS. I guess WAAS doesn't add much cost to the unit and people are familiar with the feature, so Garmin includes it. I'm against including anything just for the sake of adding more useless features. Garmin should consider dropping the WAAS support, since it's not necessary.

At any rate, you're safe leaving WAAS disabled.

Safe Mode prevents you from operating the nuvi when the vehicle is in motion. This safety feature is designed to prevent a driver from becoming distracted by the GPS and causing an accident. I find that many times I need to use the GPS while driving, so I like to set Safe Mode to Off.

Garmin Lock was already discussed previously. This feature allows you to set a 4 digit pin code that must be entered each time the nuvi is powered on. Alternatively, if you forget the PIN code, you can drive to the specific "Safe" location (usually your home address) and the unit will unlock without the PIN code. Since I doubt most thieves are familiar with the Garmin Lock feature, I leave this feature disabled. Instead, I advise taking the nuvi out of the dash when leaving the car. Plus, if my nuvi does get stolen, the very last thing I want is crooks showing up at my home to unlock the device!

Touch Tones turns on or off the tone that plays whenever you touch the screen.

Simulator Mode allows you to have the nuvi operate in simulation mode. Useful if you want to plan a trip and want to see what route the nuvi will take you, or compare the nuvi's routing results with an online engine, like MapQuest.

Figure 86: Setting Locale Preferences

These are pretty self explanatory. You can set text and voice language, time format preference, and miles or kilometers.

Figure 87: Changing the Display Settings

Color Mode allows you to set whether the nuvi 660 should use the daytime screen colors and brightness, nighttime, or automatically switch between the two. Naturally I left this set to Auto. I noticed that day/night switching is based on time of day rather than actual ambient brightness level. I don't know how much cost it would add to have an external light sensor control the daytime/nighttime screen mode, but it would be preferable. Many times I noticed that although it was definitely dark enough outside to warrant nighttime screen brightness/colors, the nuvi continued in daytime mode until it was officially "sunset" time.

Backlight Timout might be useful if you're using the nuvi on battery instead of the 12v adapter. You can adjust how long the backlighting remains on when running on battery instead of 12v adapter. In my testing I didn't change this setting.

Touch Screen is a mechanism for recalibrating the display. If you notice that the unit thinks your pressing on a different button than you intended, you may need to recalibrate the screen. I didn't need to recalibrate, but it's nice to have the ability to do so.

Splash Screen allows you to change the image that's briefly displayed when you power on the nuvi. The nuvi can use any image saved on its internal memory or SD card.

Screenshot enabled you to capture what's being displayed on the nuvi and save it off to your computer. Although this was quite useful for this review, I'm not sure how handy this is for normal day-to-day operation (other than perhaps emailing a screenshot of your trip computer, showing your top speed of 130MPH to your roommates).

27. Navigation Settings

Figure 88: Changing Navigation Settings

One of the more important configuration pages is the Navigation Settings menu, accessed by tapping on configuration -> Navigation. This is the menu you'll use to set core navigation preferences.

Avoidances can be configured to avoid certain roads or highways. More importantly, you can have the nuvi automatically avoid traffic jams (provided you're in an area with traffic data coverage and have a valid traffic subscription).

Figure 89: Setting Routing Preferences

There are three options for setting your routing preference: Faster Time, Shorter Distance, and Off Road. Off Road is useful for navigating to coordinates instead of a street address, or Geocaching. Faster Time and Shorter Distance are slightly more complex. I always leave my GPS set to Faster Time. In some cases, however, Shorter Time may be the best choice, since the GPS may route you around congested streets.

I'd like to see Garmin include the ability to have the nuvi calculate both Faster Time and Shorter Distance, present each method's estimated travel time, and then let you choose the best method for each trip. I know this would add some route calculation time, but without it this setting is of little value.