Fenix 6 Pro GPS accuracy problem

Definitely the 1s recording should be on.

1s recording wouldn't do anything for the distance accuracy. That is the "recording" rate only, not the "measurement" rate, which remains 1s regardless of the setting.

Fenix 6 being short when running on trails (which that 50k I assume was on) is a well known issue if you search this forum. The new Airoha GPS chipset used in the latest generation of Garmin watches is much more accurate on trails.

3D distance will make no difference if it is a flat run. The more elevation you have, the more difference it will make. 

If GPS accuracy is very important for you, I would anyway recommend one of the latest generation watches (e.g. forerunner 255, Fenix 7). These have an improved GPS chip. But while they are for sure an improvement, you cannot expect miracles from them either. It is just a tiny watch, with a tiny GPS antenna and extremely low power consumption, it will not be 100% accurate. 

yep, was on trails. Didn't realize that about the chipset, thanks for the info!

This sunday morning i did an official trail, 16km announce by the organization.

My F6Pro report 15.42km, so i compare this to other participants on strava, nobody report the 16km, other garmin models (even the best 745)/other vendor like Suunto/ smartphone (strava app, etc.)

14.5, 15, 15.5, etc... sometimes course organisator roundup the distance for marketing purpose maybe ;-)

gspinoza said:

No, it won't change anything. It's the accuracy of the GPS chip

What was that again ? Export completed activity as GPX to the computer, and then import exactly this GPX back into Connect web portal. Then the distance is correct ;)

9096094 said:

Notes: used GPS + Glonass; did not have "every second" or "3D distance" on since I wasn't aware of those

If you are in the UK GPS + Galileo always measures very accurately, Galileo has been visable for the last 18 months since the constellation was finally fully live.

Over the weekend I ran a 25K mountainous trail (actually slightly over 25k) and my Fenix 7, my Fenix 6 Pro and my running partners 6x all measured with 0.04 miles (60 meters of each other)

I found a bug with the F6 Sapphire as it happens and posted a bug (not distance), but you can see the F7 / F6 they are super close (both measured very close to the official course GPX that is part of the mandatory kit)

https://forums.garmin.com/beta-program/fenix-6-series/alpha-updates/i/public-alpha-23-xx/hr-dropouts-from-ant-hr-sensor-on-long-trail-run

And my running partners watch measured 15.68 miles which is 25.23k and my watches measured 22.22k and 25.26k - so 2 Fenix 6's and 1 Fenix 7 were at most 0.04 miles (60 meters) different for distance - neither my F6 Sapphire or my partner's 6x Pro was incorrect for distance or particularly short or even long.

9096094 said:

Already did a search and it seems the Fenix 6 is not the best choice for people looking for accurate distances.

Down to faulty watches / bad settings in many cases I think -  I have never seen this in 18 months, including using 4 watches at once! 

https://forums.garmin.com/outdoor-recreation/outdoor-recreation/f/fenix-6-series/301347/hrm-pro-fw-8-80-or-plus-for-improving-distance-and-pace-related-problems-for-outside-running-on-the-f6

I never have distance problems my side - some people do, but it's not a systematic issue with me or the people I run with.

In my experience with Fenix 6X, the distance accuracy varied greatly with how wooded the terrain was. On an open terrain it was plenty accurate. But on wooded trails it struggled quite a bit, loosing distance with every switchback or turn. Another factor is speed. It is fairly accurate at walking speed and may even slightly overestimate the distance. But when running fast on the same trail, the distance could easily be 5% shorter or even worse.

That is when using GPS+Glonass with every second recording (just in case someone mentions that).

Just did an 8 km run, where my 6X pro tells me it's 6.85. I did most of it on a 400 meter track. The fenix consistently measures 340-350 meter, which is almost 20% off. Really getting frustrated. This inaccuracy started a few weeks ago, and it's off during running ever since. GPS + glonass (recommended setting I heard), every second, latest software.

@Garmin, please support!!!

Note, my friend running next to me with FR955 did record 400 meters, and we confirmed his accuracy with other measurements.