The Zumo 665/660 are often way off when calculating the fastest route between two points. The maps are the latest available, there are no avoidance configured, and the settings are for fastest time, not shortest distance. The issue is not isolated to my device as we duplicated the problem when calling Garmin tech support when they used one of their devices.
While the best/faster routes is usually obtained by remaining on interstates and/or toll roads, the 665 often will instruct to exit the highway and go thru internal, slower roads. Not only is the time computed by the 665 very wrong, when considering traffic the problem becomes much worse.
When I compare the routes between two points calculated by my Zumo 665, my older Zumo 450, Garmin Base Camp, Google Maps and Apple Maps, in every single case the 450, Base Camp, Google and Apple compute the same (correct) route. Only the 665 will instead calculate a completely different (and very wrong) route which takes often 20%-40% more time to travel. Most of the issues are with the 665 not using interstates/toll roads.
In the screenshots below see the route calculated between "Smokerise Blvd, Longwood FL 32779" and "610 Glen Cheek Dr, Cape Canaveral, FL 32920". The Zumo will avoid interstates/toll roads for the first two thirds of the trip. It thinks the 63 miles trip will take 1 hour 10 minutes without traffic.
The following screenshot shows the "correct" route that takes interstate 4, Toll road 408, toll road 417 and toll road 528. That route is 71 miles long and takes 1 hour 10 minutes without traffic. This route is the same that will be provided by Google Maps, the Zumo 450, Garmin Base Camp and Apple Maps.
I created the route that the 665 calculated in Google Maps. You can see that the distance is indeed 63 miles, but that route takes 1hour 26 minutes to travel *without traffic*. Since the first two thirds are internal roads with traffic and street lights, in reality the trip, besides being very stressful, is also much slower.
This is just an example, there are many more. In short, I cannot trust the 665 to give me the correct directions at anytime. Of course if I study my trip before leaving and figure out the real best route, I can just keep on driving oven though the 665 tells me to exit, and it will eventually recalculate. But the whole point of having a GPS in the vehicle is not having to worry about studying the route in advance.
The problem is only occurring in the Zumo 660/655. My older Zumo 450 has been calculating routes flawlessly for several years now. Farmin support told me they have no idea of why these inaccurate directions are being generated. Am I the only noticing these problems...? It's very hard to believe.
