# Accuracy of your IWC?



## ReclinerTimer (Feb 10, 2019)

For those of you with an IWC how accurate has your watch been? I've had my Portuguese Chrono 2-3 years now and it gains about 8-9 seconds per day. I don't really care, but I know its not top of the line timekeeping


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## Nokie (Jul 4, 2011)

I have a 3548 and it usually stays withing +/- 6 seconds a day, which is entirely within spec.


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## fmc000 (Nov 24, 2011)

My 3713 is within +3 sec/day.


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## DutchMongolian (Jul 5, 2016)

My Big Pilot IW501002 is fast 10s a day, got it in January, but was told this is pretty normal.


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## higginsd (Mar 12, 2007)

My 377701 runs +5s. Per month...


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## Dave A (Mar 7, 2014)

My Valjoux powered Chrono gains maybe 10 secs per week.


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## MannyR69 (Aug 21, 2014)

I basically have the same question wirh my bronze BP, mine is gaining 9sec per day though it’s very consistent. 9 secs is too fast for me...


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## dkbs (Nov 2, 2008)

IWC never ever claim their movements are certified chronometers, although their movements are usually marked with "Adjusted xxx".

Usually, the standard used here is one minute per week, This also applies to JLC and even Vacheron Constantin with Geneva mark, as long as one is not a certified chronometer.

IWC is a jewel, not instrument, you are just asking way TOO much.



MannyR69 said:


> I basically have the same question wirh my bronze BP, mine is gaining 9sec per day though it's very consistent. 9 secs is too fast for me...
> 
> Sent from my iPad using Tapatalk


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## higginsd (Mar 12, 2007)

Yes, but 9s/d isn't really good. With a good regulation 4-5s/d should be possible.


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## dkbs (Nov 2, 2008)

Normally, all ETA based movements are within COSC specs, most of IWC's own movements are at 1 min/week level (10s/d), no data about Vaucher movements (such as new spitfire).

The problem is not about regulating, it is the design. Most of people will go 7750 or 2892 based watches. A handful of unlucky people pick 8 day movement, including you, which is notoriously bad in horology.



higginsd said:


> Yes, but 9s/d isn't really good. With a good regulation 4-5s/d should be possible.
> 
> Gesendet von iPhone mit Tapatalk


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## higginsd (Mar 12, 2007)

It's not me or my watch, sorry, you misunderstood.

Anyway, my BP - has a notoriously incorrect 8 day movement - is ruining at -2s/d.

Sometimes it's a problem of careless regulation and weak service (I heard about Rolex owners getting back their watch from official service with +15s - a nogo). Weak service also means that sometimes for example it's better to change the balance spring with bad amplitude, than trying to keep the price and the service time low.

Last not least sometimes it's a problem of missing service caused by the owner. Oil is not forever at the correct place...



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## fmc000 (Nov 24, 2011)

higginsd said:


> My 377701 runs +5s. Per month...


Very good indeed.


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## fmc000 (Nov 24, 2011)

dkbs said:


> IWC never ever claim their movements are certified chronometers, although their movements are usually marked with "Adjusted xxx".


In case of ETA movement, IWC buys only "Chronometer Grade" movements, therefore they should be able to run within the COSC spec (-4 / +6 sec/day). However, I remember having read somewhere (unfortunately I'm not able to find the reference, sorry) that at IWC they regulate their movements to run within 0 / +7 sec/day.


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## heb (Feb 24, 2006)

From a purely Average Daily Rate (ADR) perspective, my Mk XI Tribute pilot watch is very accurate. Awhile back, I wore it for 7 consecutive months. The second month showed a slight gain over the first month's ADR -- +2.4 versus +2.1. But then the watch began its well established slowing trend, typical of ETA/Selita movements. Each consecutive month's ADR decreased a bit over the previous one. At the end of the 7th month, the ADR was +0.4 s/d. 

I know, I know, most of us would almost kill for such a number. But ADR is only one aspect of a watch's precision. The other, and more important, part is Rate Stability. My IWC's ADR lost 2 seconds over a 5 month period. Assuming its aging curve maintains the same slope (it won't; it will get worse with time), at the end of 5 years, my watch will be running about -22 to -30 s/d. BOTTOM LINE: Great ADR (for now), but an unstable movement. If you want a long term stable movement, you must go with a Rolex watch.

heb


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## Time Exposure (Aug 13, 2010)

I have two Porsche Design Titan chronographs with the Valjoux 7750, one serviced in 2016 by IWC, the other serviced earlier this year by Superior Watch in Brooklyn. Both run +10 seconds per week, just over a second a day. For a pair of 37-year old watches, I'd say that's exceptional.


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## issey.miyake (Mar 8, 2011)

I had a Portuguese Chrono and it was +8s/d. 

Didn’t really bother me as I’d rather be early than late.


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## Lowrota (Jul 23, 2018)

Tribute to MK XI runs +5spd


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## Ricky C (Dec 24, 2021)

ReclinerTimer said:


> For those of you with an IWC how accurate has your watch been? I've had my Portuguese Chrono 2-3 years now and it gains about 8-9 seconds per day. I don't really care, but I know its not top of the line timekeeping


My Portuguese is 2 seconds per day ahead. No more sometimes a little less. It is the previous movement before going to inhouse.


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## gyang333 (Jun 12, 2010)

Old thread, but I'll play. My IWC 5021-19 that I got back from service is about +2 to +5 seconds a day so far.


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## scottomatic (Dec 11, 2021)

New BP43 seems to be between +4 and +8 a day. Have a TAG, Omega, and Sinn and this is the least accurate, but still my favorite


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## LCheapo (Jul 14, 2010)

My Portugieser chrono 371604 started out at about -1.5s/day in July, seemed pretty consistent for a while, but now it is at +3.4s/d.


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## Kirkawall (Mar 28, 2015)

My spitfire auto is still running at around +4s per week, with around 75 hours on a full wind. It's a superb timekeeper.


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## flying flynn (Aug 19, 2021)

I've posted this elsewhere, But my 3239 is exceptionally accurate. It runs about +2 seconds every three weeks. I lucked out and bought it on the used market at a time when no-one wanted one. It's secretly my favorite watch.


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## gyang333 (Jun 12, 2010)

gyang333 said:


> Old thread, but I'll play. My IWC 5021-19 that I got back from service is about +2 to +5 seconds a day so far.


Update: after just over 3 weeks since getting it back, it's closer to +1.5 to +2 s a day.


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## WTSP (May 6, 2012)

Good to hear that some owners have reasonable accuracy results with IWC. My Big Pilot 5004 is abominable. Both + or - double digits per day depending on the position of the power reserve. I discuss this topic with others in more detail here.








Is accuracy still the defining strength of the IWC...


The genesis of the Portugieser, was the need to have a highly accurate watch and the only movement in the 1930 capable of providing that exactness was a pocket watch, which then of course defined to create large watches even when small watches were fashionable. So, one could say that the...




www.watchuseek.com


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## Time Exposure (Aug 13, 2010)

Theee Porsche Design Titan automatic chronographs.

The one on the left: +0.8 seconds per day.
The one in the center:-0.9 sec. per day.
The one on the right: -4.8 sec. per day.

I can live with that! Shout out to Jack Freedman at Superior Watch Service in Brooklyn, New York, who serviced all three. Chronometer running rate on 40-year old watches is damned impressive, even if they already had IWC and Valjoux 7750 “bones.”


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## daveswordfish (Aug 17, 2010)

I’ve got a 5002 BP, an Aquatimer 2000, two pilots chronos, and a spitfire chrono.

Never timed any of em. Never noticed them being off.

Therefore, they’re spot on accurate!


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## chatterhawk (11 mo ago)

scottomatic said:


> New BP43 seems to be between +4 and +8 a day. Have a TAG, Omega, and Sinn and this is the least accurate, but still my favorite


considering the BP43. Any change in accuracy since you posted this?


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## fmc000 (Nov 24, 2011)

My 3713 used to run at 0spd when not worn (face up) and at +3spd when worn.


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## WTSP (May 6, 2012)

fmc000 said:


> My 3713 used to run at 0spd when not worn (face up) and at +3spd when worn.


Not surprising since it’s a modified Valjoux and those can be made to run very accurately.


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## 3mb (Mar 14, 2021)

Was wearing my 1973 Iwc when I saw this thread,


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## Time Exposure (Aug 13, 2010)

3mb said:


> Was wearing my 1973 Iwc when I saw this thread,


Caliber 8541? Pictures!


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## Hard_Khor (11 mo ago)

Hello,
My 5 days old Pilot Chronograph 41 runs +8s when not worn (face up). 
Then on my wrist for 12 hours: a spot on +0s
So this night i'll try crown up until 12am and will see...


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## 3mb (Mar 14, 2021)

Just checked my 49 year old yacht club,


Time Exposure said:


> Caliber 8541? Pictures!


Yes, 8541B, gains just 4 seconds a day.


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## Dave A (Mar 7, 2014)

3 weeks ago purchased a new 46mm Big Pilot IW501002.
The AD wound it to maximum before handing it over

I wore it for 2 weeks solid, and it gained about 7 secs per day.
In this time it never showed less than 6 days remaining power.
As part of the running in process, I wanted to let it run down, and the only way was to not wear it.

Last Sunday at 3pm, I fully wound it to see just how bad it would get as the days passed by - To be honest, I feared the worse!
It was rested crown up, and checked at the same time each day. The results are as follows;

Sun 3pm 0s
Monday +7
Tue + 15
Wed +23
Thurs +29
Fri +28
Sat +28
Sun 3pm +26s

So totally opposite to everything I read about it going haywire in the last few days.
A loss of 3 secs in the last 3 days is pretty spectacular in my opinion.
It's only just into the red, and if it makes it 'till tomorrow, I'll put up it's performance.

Needless to say, I shall only be winding it to 4 days, and try to keep it between 2 and 5 on he power reserve.


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## ChubbyPan (Jun 9, 2017)

My 500401 is running +3sec a day


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## Dave A (Mar 7, 2014)

ChubbyPan said:


> My 500401 is running +3sec a day


After 6 weeks of ownership I would put mine about the same.
But it's a rock solid plus 3, no matter how you wear or rest it.
It has lived most of it's short life in the 2 - 4 day power reserve, where it seems to perform well.
I am confident t will continue to settle in and slow down a touch more?
But I would sooner have a few plus seconds than an annoying minus half a second.


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## drmdwebb (Apr 17, 2020)

I just posted a new thread and noticed this one:

IWC 89365 performance

Mine is < 2 spd as worn.


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## Nate11 (Feb 17, 2021)

Hard_Khor said:


> Hello,
> My 5 days old Pilot Chronograph 41 runs +8s when not worn (face up).
> Then on my wrist for 12 hours: a spot on +0s
> So this night i'll try crown up until 12am and will see...


That’s surprising. I know it’s not COSC but that seems excessive for a watch at that price point.


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## Michael8282 (9 mo ago)

Aquatimer IWC 329001 currently is running +2.6 sec a day. During winter is +1 sec a day, during summer +4 sec a day. I always put my watch face up during night. If I put crown up, it slows down.


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## jmerino7 (Jan 11, 2011)

DutchMongolian said:


> My Big Pilot IW501002 is fast 10s a day, got it in January, but was told this is pretty normal.


My 2020 Big Pilot ran at +15 seconds a day. Traded it for the Le Petit Prince chrono, that one runs +3 fast. Sometimes in-house calibers are not better than an ETA/Sellita caliber.


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## olske59 (May 26, 2019)

ReclinerTimer said:


> For those of you with an IWC how accurate has your watch been? I've had my Portuguese Chrono 2-3 years now and it gains about 8-9 seconds per day. I don't really care, but I know its not top of the line timekeeping


My 1970 Yacht Club still runs within COSC specs and has only received routine maintenance over the last fifty years.


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## Nate11 (Feb 17, 2021)

jmerino7 said:


> My 2020 Big Pilot ran at +15 seconds a day. Traded it for the Le Petit Prince chrono, that one runs +3 fast. Sometimes in-house calibers are not better than an ETA/Sellita caliber.


That’s ridiculous. I’m not at all a stickler for just how accurate my watches are but +15 a day means you have to fix the time at least every week. Not okay at that price point and from a brand like IWC.


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## drmdwebb (Apr 17, 2020)

jmerino7 said:


> My 2020 Big Pilot ran at +15 seconds a day. Traded it for the Le Petit Prince chrono, that one runs +3 fast. Sometimes in-house calibers are not better than an ETA/Sellita caliber.


If it ran that far off you should have had it regulated. I'm sure it could have run much better.


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