Sonnsteine Trail GPS Testing: A History of Data

This trail between Ebensee and Traunkirchen is one of my fast favorites for GPS watch testing – so it’s time to finally put all the comparison data somewhere. Here goes!

Sonnsteine Data

2020-02-24 Suunto 77.83 km771821T-E
2020-02-24 Suunto 9 Baro6.69 km787824T-E
2020-02-24 Polar Vantage V6.53 km825820T-E
2020-02-24Garmin fenix 6X Pro6.95 km830788T-E
2019-06-01Ambit3 Peak7.64 km**E-T
2019-06-01 Suunto 9 Baro7.12777740E-T
2019-06-01 Suunto 57.33745703E-T
2019-06-01 Polar Vantage V6.84770740E-T
2019-06-01 Coros Apex (3D)7.12807768E-T
2019-05-25Coros Apex6.73752768T-E
2019-05-25Suunto 9 Baro7.25754757T-E
2019-05-25Suunto 57.32726733T-E
2018-12-26Suunto 9 Baro7.08802831E-T
2018-12-26Garmin Instinct7.1713171336T-E
2018-07-19Ambit3 Peak7.32761769T-E
2018-07-19Suunto 9 Baro6.95742767T-E
2018-07-19GPS TrackPOD6.7832836T-E
2017-10-01fenix 5X8.07772807T-E
2016-02-06Ambit3 Vertical7.4800839E-T
2015-12-30Ambit3 Peak7.3812835T-E

The Direction indicated here means whether the tour was done from Ebensee to Traunkirchen (E-T) or the other way round. That one recording from the Ambit 3 Peak only has a distance value because I promptly lost/forgot the watch at the end of that tour… Stupid story.


On average, the recorded track distance ends up at 7.2 km.

Looking at everything in the direction from Traunkirchen (T) to Ebensee (E), the average ascent recorded is 783 m, the average descent 797 m.

(For this calculation, I left out the data from the Garmin Instinct, which is too far an outlier to be considered.)

Funny thing: It all works particularly well as a sign of how problematic map data is…

Map Data

Plotting this same route (or the route as it would be, according to maps*), the results are rather interesting:

Movescount and plotaroute seem to both use OpenStreetMap data and end up showing 6.46 km distance… but plotaroute gives an approximate ascent of 667 m.

Movescount shows this route as having 760 m of ascent (a good 100 m more) and 790 m of descent.

The Suunto app gives this route 6.47 km and an ascent of 683 m…

What Gives? Differences Map vs. Reality

*Meanwhile, on the ground, the distance is likely to be different.

For one, I tend not to always take exactly the same route. In winter conditions, it is not even visible everywhere.

Secondly, one walks back and forth a lot more in reality than maps would have it, simply because there is a big difference between a scaled map and reality on the ground.

Who’s to know where exactly the path is – all the more so as it includes a climbing section!

Finally, for altitude recordings, it can be an issue what the environmental conditions (changes in air pressure because of weather changes) were like. And it is certainly an issue how the algorithm used in the respective watch interprets pressure changes as altitude changes.

It’s all a bit different again with those watches – looking at the Suunto 5 now – which do not have a barometric altimeter but only use GPS altitude calculation.


As usual with such data, some outliers as well as trends are noticeable – and it’s difficult to really make justifiable conclusions.

(Ah, don’t you love it that I keep letting reality interfere with me just telling you which watch is the best? :-p )

Distance (Average)s

Garmin fenix 5X, 6X vs. Suunto Spartan Ultra

It is noticeable that the fenix 5X recorded considerably more distance here than the other watches, overall (on average) – 8.07 km.

If you look at the table above, you can see that I used it at the same time as a Suunto Spartan Ultra. The Spartan Ultra also recorded a distance slightly above the average, but not so much.

There’s something missing, though, as the fenix 5X recording here was a one-off whereas the distance data from the Spartan Ultra is an average from two recordings (on which it once, used at the same time as the fenix 5X, gave 7.13 km total, the other time 7.83 km).

The Garmin fenix 6X Pro recorded a distance (6.95 km) close to the average (of 7.2 km)…

Ambit 3 Peak, Suunto 9 Baro

Only the Ambit 3 Peak and Suunto 9 Baro have been on that trail for 3 or 4 (by now, 5) times, respectively…

In that, the S9B has recorded between 6.69 and 7.25 km; the A3P between 7.3 and 7.65 km.

(I’m sure many people would like to claim that this must be because the Ambit3 has better GPS reception, but it could just as well be different algorithms. Or something else…)

The New Suunto 9 Baro Algorithm

The decline in distance recorded by the Suunto 9 Baro is quite certainly due to its GPS algorithm.

It now records much “nicer” tracks than before, without the meandering on straight courses that it used to show – but paid for by less distance being recorded.

Suunto 7 Issues

The GPS track recording on the Suunto 7, in contrast, is (still) rather too sensitive, often interpreting sudden turns as longer distances – and of course, also recording longer distance overall.


Interesting also to have a look at the data on elevation gain/loss.

I am pretty sure I have always entered the data correctly, all counted in the same direction of travel… and still, sometimes, more ascent than descent is recorded. According to all data I know, there is more descent than ascent on this route.

But, how much?

On average, from the recorded data, I get to 783 m of ascent, 797 m of descent.

On online maps with route plotting (to repeat the above here), there are ascent values of between 667 m, 683 m, and 760 m in ascent; 790 m in descent… and maybe something changed in their data, by now. (I also don’t know why I’ve only noted down one value for descent anymore…)

In Conclusion…

The summary and conclusion can only be one thing: Road marathon courses can be measured to exact distance along the best line – and even then, not everyone could run them exactly like that.

On a trail like this, there will always be some variation, in the course taken, in the data recorded, and in the interpretation of that data by the different watch’s algorithms.

In constellation of satellites, making for different visibility.

And so on…

Meaning, you’d better focus on the different offerings of different watches. What functions and what user interface appeal to you. Not on some peculiarities in data.

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