If you are considering the Forerunner 165, here is what concretely changes with the newer Forerunner 170 — both Garmin running watches in the standard 43 mm (non-Music) format.

Short answer

Neither watch is universally "better": the right choice depends on your priorities. The 165 is the earlier-generation 43 mm Garmin option, while the 170 is the newer 43 mm standard model with a 1.2-inch AMOLED touchscreen. According to the manufacturer, the 170 adds recent Forerunner-series training features; check each manufacturer sheet for the exact feature list and announced battery life.

Key differences

  • Generation: the 165 is the earlier-generation 43 mm Garmin option, while the 170 is the newer 43 mm standard model.
  • Display: both have AMOLED; on the 170 the display is a touchscreen and is specified at 1.2 inches per the manufacturer sheet.
  • Training features: both offer Garmin's training features (daily suggested workouts, Garmin Coach according to the sheet). The 170 introduces recent Forerunner-series features. Compare both sheets for the exact list.
  • GPS and navigation: both record routes via GPS; per the manufacturer sheets neither adds full mapping from the higher ranges.
  • Music: both watches compared here are standard/non-Music — no onboard music storage; music is controlled from the phone. Music variants are separate products.
  • Battery: each manufacturer sheet announces its own battery life; it varies with use (GPS, display). Compare the announced values before deciding.

Forerunner 165 strengths

  • 43 mm AMOLED display built for running
  • Garmin training features (daily suggested workouts, Garmin Coach according to the sheet)
  • Earlier-generation 43 mm option in the Garmin range

Forerunner 165 tradeoffs

  • No standalone music playback (non-Music model)
  • Some higher-range features are not included
  • Announced battery life varies with use

Forerunner 170 strengths

  • 1.2-inch AMOLED touchscreen
  • The newer model, with recent Forerunner-series training features
  • Wrist-based heart rate and built-in GPS

Forerunner 170 tradeoffs

  • Standard 43 mm format: no onboard music storage (the Music variant is a separate product)
  • Announced battery life varies with use: compare the sheets
  • Some higher-range features remain absent

Who should choose the 165?

  • You want Garmin's training ecosystem on an earlier-generation 43 mm watch.
  • A touchscreen and the very latest range features are not a priority.

Who should choose the 170?

  • You want the newest model of this tier, with a touchscreen.
  • The recent Forerunner-series training features interest you.

Verdict

The right choice depends on your priorities: the earlier-generation Garmin option (165) or the newer touchscreen model with recent features (170). Pricing can change, so check both before deciding. Verify the exact feature lists on each manufacturer sheet before deciding.