Garmin Forerunner 570 vs fēnix 8

First, the mode mismatch nearly every table gets wrong

You will see these two compared as “18 hours against 35”. Those are real Garmin numbers and they describe different satellite modes. The 570's 18 hours is its GPS-Only figure; the fēnix 8's 35 hours is all satellite systems plus multi-band. Quoting one against the other is the single most common way spec comparisons in this category mislead without printing a false number.

Garmin publishes every mode for both watches, so there is no excuse for the mismatch. Matched properly, the gap is larger, not smaller.

The 570 figures come from Garmin's Forerunner 570 product page and the fēnix 8 figures from the fēnix 8 Series owner's manual battery table, with the Gesture screen timeout. Both are manufacturer-stated and neither has been independently verified by anyone, including us.

A note on our own arithmetic, because it uses different modes

The cost-per-GPS-hour figures this site prints use 18 hours for the 570 and 35 hours for the fēnix 8 — GPS-Only against all-systems multi-band. That is deliberate and it is a compromise: each is the figure that watch's page has carried since launch, and changing one now would silently move every derived number on every page that renders it. We would rather name the inconsistency here than quietly repair it and move a dozen published figures. If you want the strictly matched comparison, it is the table above: 14 hours against 35.

The rest of the specification

What you are actually buying with the extra money

The gap between the two is $194at today's prices. Three things cross that gap, and none of them is data.

Maps. Real cartography with your route drawn on it is a different tool from a breadcrumb line, and the difference only matters when you need to leave the route rather than follow it. We wrote a whole page on whether you actually need maps because it is the single most oversold feature in this category, and for most road runners the honest answer is no.

The case. Dive rating, tougher materials, and a build meant to survive impact. If your watch meets rock, this is worth paying for. If it meets pavement, you are buying a specification you will never test.

Endurance.This is the real one. Thirty-five stated hours in the accurate satellite mode against fourteen is not a marginal difference — it is the difference between finishing a hundred-miler on one charge and not. If you race long, the fēnix is not a luxury.

What does not cross the gap

Both watches carry the same generation of Garmin Elevate optical sensor and the same multi-band receiver, both compute the same training metrics from it, and neither has been independently validated that we could find. The 570 records the same heart rate, the same VO2 max estimate, the same training load and the same positioning data. A reader upgrading for better numbers is buying the wrong thing.

If heart-rate data on intervals is the actual complaint, neither watch solves it — they put the same sensor in the same place on the same wrist. The published fix is a chest strap, and it costs a fraction of either watch.

The thing to check before you buy the fēnix

Garmin announced the fēnix 9 and fēnix 9 Pro on 25 August 2026, which makes the fēnix 8 the previous generation. It is still on sale and it is unchanged by the announcement — and outgoing flagships are exactly where real discounts appear. That cuts both ways: the price you see today may be unusually good, and it may also be a line Garmin is winding down. The Forerunner 570, launched in May 2025, is current.

How our rubric scores them, and why they are close

The fēnix 8 scores 7.5 and the Forerunner 570 scores 7.3. That is a narrower gap than the price difference suggests, and the reason is the two columns that decide it. They tie on evidence — nothing published for either, 30% of the score each way. The fēnix wins hardware, coverage and endurance. The 570 wins cost per capability by a wide margin, which is most of what pulls it back level.

A rubric that weighted features alone would put a large gap here. Ours does not, because the premise of this site is that what a device can be shown to measure matters more than what it can be shown to do.