ETA Calculation

Normalized power (NP) would improve it quite a lot

As Andre said using Normalised power or even a rolling average that’s at least long enough to take into account the distance yet to travel. For sure instantaneous power is utterly pointless as nobody can ride like this. I can see the feature works but only for a developer not for the real world. 

I recommend using as a starting guide ETA that could be used in the menu to have 70% of FTP like a base Tempo training effort that fit riders can sustain upto 3 to 4hrs. That could be used for the initial ETA when riding until enough data has been recorded via normalised watts to have an idea of the actual % FTP your pushing. 

I would love to debate it with anyone interested in this.

To add using a aerobic wkg that’s set roughly where the average cyclist is training that’s based on your own ability (70% WKG at FTP). This would allow the rider to see in the menu & specific ride data how long the ride is likely to take them.... To me that would seem also a very handy metric for the customers that’s technically easy to add? 

an example would be, customer is looking at riding Mont Ventoux he looks at the ETA & sees it will take him 2hrs even though the distance is only 21km = customer can then make a valid decision to take it on or not.

Adding ETA to the menu or pre ride course information screen could be even made fairly accurate if the App was to store a riders Mean Max data. That’s a curve that would show the duration a rider is capable of for each power. But that would also presume a rider will go flat out....I never do this unless someone is waving some cash prize haha  ;-)

The garmin virtual partner calculation is spot on for me..
It is crazy accurate.. 

One would assume that one garmin would have access to the other garmin, so one garmin would not have to reinvent the wheel since the other garmin already did the work and it is proven.. 

Or am i daft?

ETA right now is based on the virtual speed maths inside the app. If you cycled at spot on 200watts the ETA will be correct probably to the second. The issue is nobody on earth can actually ride at spot on 200watts hence it just needs to be based on something that’s been smoothed out like say your 10min rolling average 

That's make a lot of sense to me too

ETA still completely unreliable,....any good news on improvment?

Seems like ETA calculation has some inherent difficulties, including the nature of the terrain (i.e., hilliness and lumpiness).  I was happy just to be able to turn it off as it was not very important to me and kind of a nuisance.

As Phil70 suggested taking i to account last 10’ NP will make it reasonable precise