fenix 6 pro run distance accuracy ??

I had a lot of faith in my Fenix 6 Pro however I ran with someone who has the Fenix 3 (I upgraded from 3 to 5 to 6. Anyway his GPS map is much cleaner and accurate, also there was a 250m difference over 10km. It seems like a lot of difference. I know you could argue that I may be the more accurate but looking at the GPS maps I suggest the 3 is the accurate on this occasion. 

• I’m sorry if you misunderstood my words.
• Since 2010 I bought at least four Garmin watches, so we can’t say I didn’t give Garmin a try. The FR610, the Fenix 3, the 735XT and the Fenix 6. Basically the FR610 was the most accurate and i still have it. To di comparisons. To make it clear, IMHO, any GPS watch who has a distance measuring accuracy at or above 2.5% is rubbish and, once again IMHO, anything above 1% accuracy can’t be used as a good training tool. 
  Once again, the Fenix 6 it’s a very nice watch, an SUV that makes it a great daily driver, but when it comes to tracks and distance measuring it fails really bad. Even the Apple Watch is doing better.

Beside, I don’t feel like going out of topic, but how about the horrible f6’s BT connection?

cfimarco said:

any GPS watch who has a distance measuring accuracy at or above 2.5% is rubbish

Agreed.  But not everyone has this percentage with their F6 as you claim with yours.  Without taking analysis from everyone, we can't say the F6 is at or above 2.5%

cfimarco said:

anything above 1% accuracy can’t be used as a good training tool. 

You may be setting your standard too high when it comes to GPS wearables and setting yourself up for disappointment.  After a search, most; if not nearly all GPS wearables have a accuracy error greater than 1%.

that is true in terms of strava being the standard - I have wondered that - my assumption is that Strava uses the data collected from all users to achieve a "norm" - maybe that is not correct - and maybe the Fenix is correct and everyone else is off - but it seems from all the Re to this that there are issues with accracy - 

and I said a .4 difference - ummm - 8.3 to 8.7 - is a .4 difference - I said about a .5 difference over 8 miles - 

I had FR610 and yes, it was pretty accurate. I switched to Suunto watches for a while, which were even more accurate than FR610. Now back to Garmin with 6X, distance and instant pace accuracy disappoint quite a bit. Once distance correction is applied in Strava, it is OK, but the distance on the watch during a run may be up to 5% short compared to what it ends up being after distance correction.

I also did side-by-side comparisons with Suunto 3 Ambit, which is probably one of the most accurate GPS watches. What I noticed is that on open terrain Fenix 6X keeps up with Suunto 3 Ambit just fine. But once I get on tree covered trails is starts lagging behind, and the less straight trails are the more it falls behind.

Clearly Fenix 6 applies some algorithm to compensate for lower strength GPS signal - some sort of filter than seems to smooth the pass on which the distance is calculated. It seems the lower strength GPS signal is the more smoothing it does, which makes it consistently short on trails with a dense tree coverage. 
 

The shorter distance displayed Vs the pure GPS distance is well known if you read this forum. And after checking with other brands, they ALL do some software change on the distance. And since all watches now use the Sony chipset, it's not as accurate as the older chipsets. We have traded accuracy for battery life. Which we don't all need...

• Garmin is shortening, and if it works well in some cases (in bad city canyons for instance, where the GPS distance is really too long), in others it can be a real problem
• Suunto 9 is shortening less with its algorithm, but its GPS performances are less good than Garmin. So overall, it's not doing much better than Garmin
• Polar, I didn't try yet
• Coros Vertix is the best choice I tried with the Sony chipset. They do a minor correction, and have the best GPS results, almost each time. It's clearly their strength. 

So yes, 1000$ for a sport watch with less good GPS results than before is very frustrating. We pay for the great battery life, and the tons of other features which are more or less useful. GPS accuracy is one of the most important features, so it can be a show stopper for some. 

Solutions : the Vertix, another Garmin watch less affected by the poor GPS results (seems that the 9xx are doing better), the Polar Grit X maybe, or add the Stryd (but when you walk... It's less accurate). 

Or wait for a future model, it should include the new Sony chipset, which can receive dual frequencies (which is different from different satellite constellations). Hard to say yet if it will really improve the GPS accuracy. But on a mobile, dual frequency + several constellations is showing very promising results, since it can eliminate the "rebounds" of satellite signal on buildings or mountains. But in a watch, without 45 satellites and with a smaller antenna ? Hard to say yet. But if it can improve it enough, it could make the Fenix finally a great watch without any major flaw.

yes - I seem to have noticed the same thing - it is disappointing because I run mostly trails - thanks for your feedback -

thanks for such a thorough discussion - i appreciate the feedback -