Almost everyone knows a standalone car GPS will correctly guide them to their destination.
But some Garmin models can provide guidance of a different sort - if you are willing to shell out $100 or so for a little-known add-on called ecoRoute HD.
Instead of dealing with maps and routes, this little gadget focuses on the internal workings of your car's engine - and as the name implies, perhaps can help you squeeze a few extra miles per gallon from every drop of that increasingly expensive gasoline.
With prices now hovering around $4 a gallon, that's a good thing.
When I first heard about this gadget, quite by accident, I was a little incredulous. After all, what in the world does a GPS unit have to do with how your vehicle's engine is performing? But in a world where GPS competition is intense and prices have fallen precipitously, one assumes Garmin is looking for every advantage it can to distinguish itself from other competitors. As far as I can tell, Garmin is the only company with such an option.
And what an interesting option it is, especially if you are a gearhead curious about what's going on inside your engine at any given moment. EcoRoute HD taps into that information by plugging into your vehicle's OBD-II port - basically a hot line to the computer that controls and monitors the engine. Almost every vehicle built since 1996 has one.
Auto mechanics have a device that plugs into the OBD II port to diagnose problems when you take your vehicle in for repair - like when your "check engine" light comes on. EcoRoute HD does the same thing, except it monitors your engine all the time and transmits that information via a wireless Bluetooth connection to your Garmin GPS. (Only certain models are compatible and a few vehicles are incompatible. Check Garmin's website, garmin.com, for more details.)
The actual ecoRoute HD device is a black chunk of plastic about the size of a smartphone, but a bit fatter. After you plug it in, you can use the supplied double-sided tape or plastic ties to secure it under your dash. (The OBD-II port is typically under the driver's side of the dash.) You then have to pair it to your GPS unit, as you would any Bluetooth device. It automatically reconnects every time you start your car.
Now comes the fun part. The GPS has an "ecoRoute" option in the menu, which expands to include several new categories once the ecoRoute HD is detected and functioning : Gauges and Mileage Report.
Gauges is mainly for the gearheads because it provides a lot of detailed technical information about what's going on inside the engine in real time. Some of gauges, like the speedometer and tachometer, are pretty familiar. Most of the rest are not and will vary depending on the vehicle.
In my late model Honda Civic, I get to see things like the exact degrees of timing advance and intake manifold pressure, as well as the coolant temperature, engine load and the volts reading during battery charging (If you are old enough, you can probably remember when all cars had an amp gauge, which is what this essentially is.) You can view five gauges at once and each gauge can be set to report one of three or four different functions.
More useful, in my view, is the mileage report page, which reports real-time miles per gallon, which I was surprised to learn varies from as little as 5 to more than 100 depending on conditions, along with a more useful average miles per gallon reading. Many newer vehicles have built-in systems to report this information, but my Honda does not, so I was glad to get this functionality. The same mileage report page shows how much fuel has been used and its cost (based on data you enter at each fill up). And if you are one of those super environmentalists worried about your carbon footprint, ecoRoute reports that, too (just in case you want to buy carbon credit offsets to balance the CO2 produced by your fuel consumption). By default, the GPS reports miles per gallon and its cost at the end of every trip.
A third menu option, ecoChallenge, turns your efforts to improve driving efficiency into a game. With the help of ecoRoute HD, a color-coded graph is generated and shows how well you are doing on things like acceleration, speed and braking, along with an overall score. If you do well on all fronts, you get a high score and the bars are all green. Do a little worse, the bars turn yellow. Do lousy, the bars turn red.
Not impressed? How about this one: If your vehicle's check engine light pops on, you no longer have to drive to a garage and pay a mechanic big bucks to find out what it means. The ecoRoute HD unit will not only tell you exactly what's wrong, it probably will allow you to reset the switch to turn off the light. That alone may make it worth the cost of purchase.
Admittedly, the ecoRoute HD is not for everyone. Many motorists will have little interest in the technical details of how their vehicle is running or care about MPG, especially given the $100 price tag. But for gadget freaks and gearheads, it's worth a look.
Tony Briggs has been a technology columnist in the Daytona Beach area for more than 20 years.