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Changing KPH dial to MPH dial
Posted: 03 Apr 2014, 21:13
by sternal
Sort of hijacking this post
https://club8090.co.uk/forum/viewtopic.php?f=39&t=129536" onclick="window.open(this.href);return false;
If I fitted these dials to my van which has a KPH dial would 30mph on the new dial actually be 30mph ? or is the wheel/cable regulated to be in KPH ?
I know this sounds like a really stupid question but hey ho !
Re: Changing KPH dial to MPH dial
Posted: 03 Apr 2014, 21:52
by clift_d
Provided the markings on the new dial face are set out correctly for your speedo, then it shouldn't make any difference as the speedo cable spins in a fixed relationship to the wheel rotation.
Re: Changing KPH dial to MPH dial
Posted: 03 Apr 2014, 22:04
by sternal
...and Id have no way of knowing that until I fitted it and tested with a satnav ...
gotta be worth a punt unless anyone knows any better ?
Re: Changing KPH dial to MPH dial
Posted: 03 Apr 2014, 22:33
by clift_d
sternal wrote:...and Id have no way of knowing that until I fitted it and tested with a satnav ...
gotta be worth a punt unless anyone knows any better ?
Look at the image of a replacement speedo dial
here which has both KPH and MPH markings. All you will be doing with your stickers in changing from KPH to MPH will be to put a new set of markings on the dial. If your KPH dial has markings set out like this image, and your sticker has MPH markings that also match the image then you're good to go. No need for a satnav.
Simples.
Re: Changing KPH dial to MPH dial
Posted: 03 Apr 2014, 22:47
by California Dreamin
The trick, is to get the needle refitted correctly with the right level of pre-load (spring tension against it's stop 'pin'.
Also...bare in mind that the milometer & trip meter will still be reading in Kilometres.
Martin
Re: Changing KPH dial to MPH dial
Posted: 03 Apr 2014, 22:49
by sturtywurty
Looking at it I'd say no.
The km/h Speedo starts at 20km? Which equates to approx 12.5mph where the mph Speedo would read 10mph.
The km Speedo is geared around 500 and the mph 805 iirc.
A quick calc (and I'm probably wrong) shows that the discrepancy will range from 25% to near 10% as the speed increases. 20kph = 12.5mph and 180kph = 111 mph (top and bottom of the dials).
That said, a guy on the other thread contacted them about the clock facia and they were pleased to oblige, if I'm right, and the 2 won't match up I'm sure they'd be able to reposition a few of the speeds and therefore offer a 'cheap kph to mph' conversion.
If of course you take the punt (it's only £5) and I'm wrong then make sure you let me and everyone else know as I'm sure you're not the only one interested in it.
Re: Changing KPH dial to MPH dial
Posted: 04 Apr 2014, 07:55
by sternal
by sturtywurty » Yesterday, 22:49
Looking at it I'd say no.
The km/h Speedo starts at 20km? Which equates to approx 12.5mph where the mph Speedo would read 10mph.
The km Speedo is geared around 500 and the mph 805 iirc.
A quick calc (and I'm probably wrong) shows that the discrepancy will range from 25% to near 10% as the speed increases. 20kph = 12.5mph and 180kph = 111 mph (top and bottom of the dials).
That said, a guy on the other thread contacted them about the clock facia and they were pleased to oblige, if I'm right, and the 2 won't match up I'm sure they'd be able to reposition a few of the speeds and therefore offer a 'cheap kph to mph' conversion.
If of course you take the punt (it's only £5) and I'm wrong then make sure you let me and everyone else know as I'm sure you're not the only one interested in it.
Based on your impressive calculations which sound correct Im not going to take the punt even if its just £5, to spend 3 hrs and risk braking brittle plastic for it to show a non correct reading isn't worth it.
I'll get my coat...
Thanks all

Re: Changing KPH dial to MPH dial
Posted: 06 Apr 2014, 20:21
by jpennington
Maybe a naff response, but why would you want to change?
Given that you can't change the odometer, without massive cost; a little mental arithmetic whilst driving is no big deal - 50 kph is near enough 30 mph, 80 kph is 50mph, 100 kph is just over 60 mph, and 120 kph is 75 mph.
I have seen 135 kph on my speedo (in Germany) but that was a few years ago.
I've been happily running on the original kph markings for the past 28 years - and they do help a bit on the continent - where you probably need to concentrate a bit more, so less time for maths.
jp
Re: Changing KPH dial to MPH dial
Posted: 06 Apr 2014, 22:26
by Jakemate
My clever mrs got an image of a mph speedo off google images, resized it and printed it on good quality paper then we stuck it on the dial over the original one.
I can't tell it's not the original and all for the cost of a sheet of paper and a bit of printer ink

Re: Changing KPH dial to MPH dial
Posted: 17 Apr 2014, 15:47
by crazydiamond
My syncro with none standard wheels/tyres has a speedo thats slightly less than useless, so I invested in a GPS speedo (google it) and it works really well. No speeding tickets for me now! (I hope)
PS I can switch between KPH and MPH as well.
Re: Changing KPH dial to MPH dial
Posted: 17 Apr 2014, 20:24
by AdrianC
jpennington wrote:Maybe a naff response, but why would you want to change?
Given that you can't change the odometer, without massive cost; a little mental arithmetic whilst driving is no big deal - 50 kph is near enough 30 mph, 80 kph is 50mph, 100 kph is just over 60 mph, and 120 kph is 75 mph.
I have seen 135 kph on my speedo (in Germany) but that was a few years ago.
I've been happily running on the original kph markings for the past 28 years - and they do help a bit on the continent - where you probably need to concentrate a bit more, so less time for maths.
This has worked for me in a wide range of stuff with KPH speedos.
Not even that much maths needed.
20mph = 30kph
30 = 50
40 = 65
50 = 80
60 = 100
70 = 115
80 = 130
As a side bonus, next time you go abroad in the van, the speedo'll match all the signs AND you'll understand better how much further you've got to go!