# Question about accuracy of Eco-drive movements



## milipili

I've been very used to Swiss made male wrist watches for almost 20 years and now I'm about to switch to Citizen eco-drive because it is not so old fashioned as the traditional ETA movements. Unfortunately, I came across the user manuals of two eco-drive watches I'm interested in that state the time keeping accuracy is +- 20 sec. per month! This made me wonder is it a writing mistake or Citizen really makes such a low accuracy quartz movements? My two last swiss watches Candino and Certina are both employing the old and trusty ETA 955.112, which accuracy is exactly -5sec/per month. What attracts me for Citizen is the solar powered movement but&#8230; I would not accept such a low accuracy from my new watch.
Please, if you own Citizen eco-drive wristwatch, let me know what is the accuracy per month or I'm missing something&#8230;
I'm interested especially in the following Citizenwatches: *AW1244-56E and *BM6935-53A


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## kdsdada0308

I think they use that number as acceptable tolerances but from the Eco-drives I've had, none were near that far off.


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## milipili

kdsdada0308 said:


> I think they use that number as acceptable tolerances but from the Eco-drives I've had, none were near that far off.


I would say that tolerances are totaly unacceptable. Please, share what is the exact accuracy seconds/per month of the eco-dives you own(ed).


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## clyde_frog

I've never had a quartz that has run towards the edge of that typical stated +/-15 seconds a month range. Never had one that runs slow either. One of my Eco-Drives runs at +4 a month and the other runs at +5.


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## Wolfsatz

milipili said:


> I would say that tolerances are totaly unacceptable. Please, share what is the exact accuracy seconds/per month of the eco-dives you own(ed).


Even Swiss watches have tolerances!

However, to answer your question. My Shadowhawk is usually .2 s/d fast when is being worn and taking light on a daily basis. It slows down quite a bit when put in the watchbox and not being worn; 5 to 6 seconds per month.

since the last DST change, it was 32.6 seconds fast up to Aug. 9th. Then its being on the watchbox and now it is just .5 ahead of atomic time.

PS. All my Swiss Line Invictas.. are usually .05 s/d past... to put it in context.

2017-10-08_12-45-56 by Wolfsatz, on Flickr


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## LightDot

milipili said:


> ...two eco-drive watches I'm interested in that state the time keeping accuracy is +- 20 sec. per month!... ...ETA 955.112, which accuracy is exactly -5sec/per month...


It seems to me that you're comparing apples with oranges. The factory spec of an ETA 955.112 certainly isn't -5s per month but rather a range of -+NN seconds and you didn't even specify it in your post. I'd be very surprised if it's much better (if at all) than Citizen's. The point is, it only makes sense to compare the factory specification of a Citizen to a factory specification of an ETA, nothing else.

On the other hand, if you want to compare the individual results people get with this watches, than comparing your -5s per month of your two ETAs to +4s or +5s that others have reported for their Citizens is exactly what you should compare. It's all very individual and nowhere close to actual statistics, but that's as good as you're going to get on a forum.

So, from this amazing statistical population of 4 watches or so, I'd say these movements are in the same accuracy range. YMMV.


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## GaryK30

I have three non-atomic Eco-Drives. The last time I checked, they were running as follows:

+4 sec/month (manual spec +/-20 sec/month)
+6 sec/month (manual spec +/-15 sec/month)
+14 sec/month (manual spec +/-15 sec/month)


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## clyde_frog

So from what I can find out that ETA 955.112 is rated for "+/- 2-3 minutes per year" or in other words, up to +/- 15 seconds a month like nearly every other quartz watch.


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## Abacab

milipili said:


> I've been very used to Swiss made male wrist watches for almost 20 years and now I'm about to switch to Citizen eco-drive because it is not so old fashioned as the traditional ETA movements. Unfortunately, I came across the user manuals of two eco-drive watches I'm interested in that state the time keeping accuracy is +- 20 sec. per month! This made me wonder is it a writing mistake or Citizen really makes such a low accuracy quartz movements? My two last swiss watches Candino and Certina are both employing the old and trusty ETA 955.112, which accuracy is exactly -5sec/per month. What attracts me for Citizen is the solar powered movement but&#8230; I would not accept such a low accuracy from my new watch.
> Please, if you own Citizen eco-drive wristwatch, let me know what is the accuracy per month or I'm missing something&#8230;
> I'm interested especially in the following Citizenwatches: *AW1244-56E and *BM6935-53A


Most quartz watches I have owned have run fast and ended up about +20 at the end of the month. When you consider that is +4 minutes a year you can't really argue with that accuracy. Nevertheless, if you want a Citizen Eco-Drive with unquestioned accuracy try the radio controlled versions that sync nightly with radio towers throughout the world. There are a number of towers worldwide (Denver, CO in the U.S.) and these watches will be spot on as long as they receive the signal at least once a week. This is a good investment if you are an absolute stickler about the accuracy of your timepiece, and the radio controlled watches don't cost much more than the regular Eco-Drives, and they are much cheaper than their satellite counterparts.


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## mfunnell

The other important variable to note is whether the watch is being worn or not. Unless temperature-compensated, an un-worn quartz watch is likely to be less accurate than one which is being worn, since they're designed to operate most accurately at 'wrist temperature'. My Citizen eco-drive runs about +6 seconds/month when unworn. I've not worn it enough to know how accurate it would be if I were to wear it continually for a month.

...Mike


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## jerouy

Buy an ultra-thin dressy Eco-Drive that does not have second hand.
Mine doesn't. I have to adjust it twice a year for DST changes, during which no noticeable time difference occurs -- keyword here is "noticeable".


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## domayotte

I don't have either of the models you are looking at, but I have a BL8000-54L Eco Drive, and it runs about +4 per month. I've found it to be accurate and reliable. 


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## cave diver

interesting discussion. finally enough to get me to download a watch accuracy tracker. cheers!


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## sticky

My only Eco-Drive is atomic so I can't help a deal there and I suspect that the opinion of a guy who can live with +20 SPD on an auto doesn't carry a deal of weight when we're talking +- 20 SPM.


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## Slm643

All you need is a Spore Drive watch then it can be any time you want! 

Sent from my LG-H871 using Tapatalk


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## milipili

wrong post


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## milipili

Summarizing the opinions up till here I can estimate the normal deviation of eco-drives is around 4-6 sec/month but there are these exceptions of 14sec/month that are still in spec but hard to accept.
As to the radiocontrolled Citizens - unfortunately in my country of living there is no radiotower and the table top radio clock I have, receives the signals probably from at least 1500km far. It is *not a rare case* to receive wrong time and date. That is why I do not look at the radio-controlled watches. 
As to the satellite wave - they are my favorite but the price is "slightly" above the budget&#8230;
And there are these titanium eco-drives that are so beautiful and attractive but I want to be sure I won't miss the decent accuracy that I'm used to of 5 s/month of my old fashioned ETA drive. And I want to know this before I pay for new Citizen. Any helpful idea?


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## mlkman19

Not all Eco-drive movements are the same.
Citizen’s A010 Eco-drive movement in their current chronomasters is rated +/- 5 seconds per year.


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## watchuck

Whilst I would agree that a new eco-drive is likely to run well within specs - by taking other people's experiences to ascertain the true accuracy is just a guesstimate.

If accuracy is that important to you, I'd just look for another watch whereby the *manufacturers specs* are aligned to your expectations, rather than other people's experience.

As if you go out and buy one which runs at say 19 s/month, it seems you'd be upset, especially if it's been worn and/or outside of the returns period. Also worth bearing in mind that even if it appears very accuate in the first few days/weeks, this may change over time for many reasons, such as temperature, etc.

"You pays your money, you makes your choice"


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## Slm643

Citizenwatches: AW1244-56E and BM6935-53A what is the stated accuracy of these two watches? 

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## clyde_frog

milipili said:


> Summarizing the opinions up till here I can estimate the normal deviation of eco-drives is around 4-6 sec/month but there are these exceptions of 14sec/month that are still in spec but hard to accept.
> As to the radiocontrolled Citizens - unfortunately in my country of living there is no radiotower and the table top radio clock I have, receives the signals probably from at least 1500km far. It is *not a rare case* to receive wrong time and date. That is why I do not look at the radio-controlled watches.
> As to the satellite wave - they are my favorite but the price is "slightly" above the budget&#8230;
> And there are these titanium eco-drives that are so beautiful and attractive but I want to be sure I won't miss the decent accuracy that I'm used to of 5 s/month of my old fashioned ETA drive. And I want to know this before I pay for new Citizen. Any helpful idea?


Your ETA is rated for +/- 15 seconds per month, the same as most eco drive movements are. You could've got the same watch you have and had it run at -15 seconds per month.


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## Shug

I have 3 eco-drives with E168 movments which are running at approx. +2 per week measured using a radio controlled skyhawk which does a sync daily.


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## Mason Delpino

Two of my Eco-Drives (not radio-controlled) run +1 second per month. The others are between +/-4 seconds/8 seconds per month. Another option is the Satellite Wave if you're worried about accuracy. GPS signal can be received anywhere in the world. Mine hasn't been off from the exact time since I got it.


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## Bobo383

I've had my eco drive a year (bought it used off eBay) and the only times I twist the crown are to correct the date on the first of the month and to change time to/From Daylight Saving Time. It stays in sync with the clock on my phone just fine. I have not worried about the number of seconds...


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## topol2

Hi, I own 8 ecodrive watches. They are generaly worn in rotation with several Bulova Accutron II watches. They were all set at for correct time at DST time change (March 12). They all run a little fast.....and most of them right now are in the 45 second range (give or take a couple of seconds) which averages out to about 6.5 seconds fast per month. The worst one (checked yesterday) was 57 seconds fast or slightly over 8 seconds per month. If your looking for inexpensive accuracy get yourself a Bulova Accutron II. I have 2 of them both set at DST change and one is running 5 seconds fast and the other 2 seconds slow. Well within Bulova accuracy claim of +/- 10 seconds per year. But they do need a battery change every couple of years.


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## Parachronicles

Two eco drives here:


+3,5 sec/month Citizen AT8010-58E Radio Controlled (without sync in my country)
+1 sec/month Citizen CA4020-54E Super Titanium


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## Steaua

Hi milipili!
I don't have the citizen models you are asking but my Citizen Eco-drive AW0050-82E is about 8 seconds ahead per month. Like you, I was expected Citizen to be little more accurate than that. In the '80s I had a cheap Swatch and was much more accurate than that. But I really like this Citizen watch and I was thinking that I have to change the time every 6 months anyway, and I could adjust the seconds then.


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## Bucks

I know this an old thread, but for anyone out there reading this and considering an ecodrive I have two. One I paid twice as much for one than the other. The more expensive one is about +1 sec a month. the cheaper one is +7 seconds a month. Maybe their most accurate movements are reserved for their most expensive models, or could it be that the older ecodrives are more accurate than their newer ones (my more expensive ecodrive is also much older)?


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## MaDTempo

Are we timing thruster burns or office meetings? Of 6 Eco-drives, one of which is 20 years old, I have experienced a range of +6-7 sec/month to spot on with my Blue Angle AT (of course I live ~70 mi friends m the Ft. Collins tower so,that helps). Specs in manual likely cover the 95%ile but not reflective of the bulk of produced movements.


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## Barrister89

Citizen does have high accuracy quartz eco-drive watches such as the Exceed AR 4000, which claims accuracy of +/- 10 secs per year.


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## mi6_

I have two Citizen Eco-Drive divers both with the E168 movement. Both seem to run around +4/+6 seconds fast per month. More than good enough for me. They’re less than a minute off after 6 months.


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## mi6_

I have two Citizen Eco-Drive divers both with the E168 movement. Both seem to run around +4/+6 seconds fast per month. More than good enough for me. They’re less than a minute off after 6 months.


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## sdiegolo

I have a Citizen Eco-Drive BM8476 - 15X for 4 years. Always within +/- 4 per month.


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