Garmin 310 XT vs. Garmin 35 GPS Test

A couple of weeks ago, I was getting ready to head out for 10 miles. I had my Garmin 35 strapped to my wrist since lately, I have favored it over the Garmin 310. The primary reason being that when I finish my run and walk back in my house, my Garmin 35’s Bluetooth syncs up to my phone. My run data is automatically uploaded to my phone and to my Garmin account. This is way easier than physically connecting my Garmin 310 to my PC and letting the upload happen.

Anyway, I am getting way from my purpose here.

I glanced down at my desk to see my 310 setting there lonely and unused. Why not wear it. Hey, why not wear both them to see how they compare GPSwise.

That’s all it took. I strapped on both Garmins and headed outside. Once both had successfully locked on to the satellites, I pressed both start buttons, and I was off and running.

For the first couple of miles, both Garmins were in lock step. Then, slowly the auto laps alerts began to diverge.

By the time that I finished running 10 miles, my 310 Garmin was nearly a quarter mile ahead of the Garmin 35.

I found it interesting but I didn’t give it much more thought at the time. I have long ago realized that Garmin GPS sensitivity tends to vary from day to day. I can run the same 10 mile course 5 days in row, and 3 out of the 5 days, the Garmin would record 10 miles at a slightly different spot. Yet, this is usually within a 100 meters or so.

Then, over the next two weeks, I repeated the same experiment and over the same course. Again, the 310 reached 10 miles before the 35 with a lead of nearly a quarter mile.

One would think that the sensitivity of the Garmin watches would be similar if not the same across all modals but this does not seem to be case. Of course, the shorter the run the less the divergence. However, for an ultra-runner who measures miles to determine the length of a run I could end up pounding the dirt for several more or less minutes depending on which Garmin is believed to be most accurate.

Wanted to share this info; in case others saw similar results with their Garmins. Just know that is not specific to anyone one runner. 

Kickin’ up the trail dust

The Cool Down Runner