Does anyone know how (or if) you can change the way the NAV calcs your time to destination? Normally it's by a certain speed into the miles to go but speeds vary.

The PRIUS has a feature where you can change it from freeway speeds of 55 to 60, 65 (whatever) and same with highway, surface streets, etc. This would be handy if you are traveling a L O N G distance and the limit is 70 vs 55.

Also, is there a way you adjust the screen display for certain "miles" sizes when showing the map? I think it shows 1/4 mile or something like that now. I have a portable GPS that allows you to display as low as 300ft and as much as 20 miles. Just curious.

O.K. Stupid me. I actually had the NAV manual in my desk and actually "READ" thru it a bit. I found the method to change the scaling (1/8 mile vs 1/4 or 4 miles).

Couldn't find anything about changing the wayit calculates speed & distance to match your freeway/highway/surface street speeds.

In the 2007 Navi Manual it states that the displayed time to destination "is calculated based on the posted road speed data and your current speed." I see nothing about being able to change how it's calculated. This would seem to be a pretty accurate way to do it so long as the posted speed data is accurate within the DVD...

I know that I can be sailing along and have very little time left to destination but as soon as hit traffic the time increases (sometimes dramatically -- southern CA after all......)

Meerkat - Please don't tell me that you never used the Zoom In/Out button on your Nav yet??? This lets you zoom down to 1/20th mile (264 feet or a finer resolution than your portable GPS) or as high as, well, the entire US though for most routes that will be unnecessary.

And correct - the time-to-destination is based on an average of a set speed on Freeway/Interstate roads, Minor roads, Unverified roads, etc. I think this is listed in the GPS manual and gives the approximate speeds.

I thought I have seen my time to distance change as I drove those 4+ hour trips though when I really want to get a more accurate number I just cancel the current route and re-map it and get the new timeframe. I did test this though and drove 80 mph for 5 minutes (1.3 miles/minute) instead of the 60 mph (1.0 mile/minute) that the car was guessing. This should have made for a difference of 0.3 miles/minute or a total of 1.5 miles closer to the destination than the car thought. I can't remember if, when I remapped the route, it thought I was now 1.5 miles closer. At any distance over 10.0 miles the distance rounds to the nearest mile instead of the tenth of a mile. If you want to get there quicker than the display then drive faster.

In the last 3 weeks of calling customers prior to arriving - the car has been +/- 1-2 minutes in accuracy on arrival time. For example, I called a customer at 6:36 PM and said I would be there in about 15 minutes (6:51 PM) and actually arrived at 6:49 PM. Called at 4:52 PM for arrival at 5:15 PM and arrived at 5:15 PM. Called at 3:00 PM for arrival at 3:30 PM and arrived at 3:29 PM. I'm starting to trust the display even though it doesn't know how many traffic lights or Stop signs I'll hit. It has been amazingly accurate for me and I'm finally believing in it.

--> Averaged 685 miles/week and 49.0 mpg in first year (35.7k miles from Aug 7, 2006 to Aug 7, 2007)