How accurate is your COSC watch really

[pistonheadforum]

Genuine question and interested in the spread of numbers for folk who wear a COSC watch on a daily basis.

If you can set it for a single day and find out how fast/slow it's running it would help as trying to build a database of manufacturers/models with real world performance.

Thanks in advance.

[pistonheadforum]

Barchettaman said:

Best of luck. What an utterly pointless exercise, however.

Yes it is rather, but it will help me settle a bet that COSC is a good standard and worth getting. I just need a fair few to prove a point.

There are beers involved in the bet so it's important!

[pistonheadforum]

Lord Marylebone said:

I hate to be 'that guy' but isn't this a bit pointless as you don't know the condition and use of all these watches you are asking about.

How old is the watch?
Has it been serviced?
Has it been served by an approved service centre?
How long ago was it serviced?
Has it been dropped or otherwise had the movement 'knocked'?
Is it being wound correctly, and wound enough, on a regular basis?
How is it being worn and does that affect the timekeeping?
Is it perhaps suffering from any kind of magnetism?

There are far too many variables to get any meaningful data.

I've know people who own newish COSC watches with terrible timekeeping, and I've owned old bangers of ETA powered automatics which haven't been serviced for nearly a decade, which run within about 10 seconds a week.

Indeed - completely pointless but somewhat interesting hopefully. I had always assumed that COSC meant spot on but now appreciate the whole "dial up" shenanigans overnight to bring it back inline and think that adds to the charm of a mechanical watch.


Beer has been paid in full, but interesting to hear that most people are getting COSC bang-for-buck unless they have a bigger problem with their watches.