My entry-level automatic loses about 8 seconds a day. The spec sheet lists a tolerance range, but I'm not sure how to read it or whether my measurement is reliable. Is this something to fix or something to live with?
Reply scope: address the opening question, explain the supporting record or reasoning, and state the limit of the answer.
Start with how you measured it. Comparing against a phone clock once a day for a week, at the same time, and noting the offset is reliable enough. One 24-hour reading isn't, because rate depends on wrist time, position overnight and state of wind. Average across several days before deciding anything.
Compare the observed rate with the exact caliber and cased-watch specification, if available. An example such as -8 seconds per day cannot be declared acceptable solely from its price category.
One method that often helps without any service is using overnight resting position to cancel daily drift. Many watches gain in some positions and lose in others. If yours loses on the wrist, try leaving it crown up or dial up overnight and log the result for a few nights. Some people get close to zero this way.
Regulation is possible if you want it closer. On many movements it's a quick adjustment by a watchmaker. Can you check whether the losing rate is consistent or getting worse? A stable -8 is a good candidate for simple regulation. A growing loss points to something else, such as falling amplitude, and regulation alone won't fix that.
A correction to a common belief: an automatic doesn't need to match a quartz watch to be healthy. Consistency matters more than the absolute figure. A watch that's reliably -8 every day is easy to live with, since you correct it once a week. One that swings from +10 to -15 is the real concern.