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speedo oddmeter inaccurate

Posted: Fri Sep 30, 2011 5:05 pm
by mentaliss
against my sat nav speed reading my speedo is reading 7-10mph faster. (When we purchased the vehicle in June the vehicle supplier in Southampton changed the dial facia) to read mph. I've since complained this difference is too much they say that they can move the needle to get the correct reading??????? we have just returned from venice and the oddmeter indicates that we have done 979 kilometers or mileage, not sure any longer which! in both cases this is also wrong...can anyone advise if this is a problem that can be fixed?

Re: speedo oddmeter inaccurate

Posted: Fri Sep 30, 2011 5:59 pm
by skater
One thing to consider/check:

When my rear tyres were standard size ie 215/65/15 my speedo read 60mph
but the satnav said 56mph.

I now have 225/70/15 on the back and the speedo and satnav read the same ( +- half mph ish ).

What size are your tyres?

In terms of your Venice trip, how many miles by satnav? If you know that you could convert to Kms
then see which is closer to the bongo odo reading of 979.

Someone will probably be along with a good way to work it out- links to tyre size conversion calculators etc.

James

Re: speedo oddmeter inaccurate

Posted: Fri Sep 30, 2011 7:25 pm
by David Edwards
yep prob find it's the tyres, same as mine, I actually prefer it like it is, helps with the dreaded speed cameras,lol.

Re: speedo oddmeter inaccurate

Posted: Fri Sep 30, 2011 7:31 pm
by teenmal
mentaliss wrote:against my sat nav speed reading my speedo is reading 7-10mph faster. (When we purchased the vehicle in June the vehicle supplier in Southampton changed the dial facia) to read mph. I've since complained this difference is too much they say that they can move the needle to get the correct reading??????? we have just returned from venice and the oddmeter indicates that we have done 979 kilometers or mileage, not sure any longer which! in both cases this is also wrong...can anyone advise if this is a problem that can be fixed?

Hi
Your vehicle supplier should be able to zero the needle for you,the the speedo will be clocking up in KMs,you can check it with your sat nav.Or travel at 60 mph for one minute =1mile not 1.6 if 1.6 its KMs..

Cheers..

Re: speedo oddmeter inaccurate

Posted: Fri Sep 30, 2011 7:44 pm
by mentaliss
skater wrote:One thing to consider/check:

When my rear tyres were standard size ie 215/65/15 my speedo read 60mph
but the satnav said 56mph.

I now have 225/70/15 on the back and the speedo and satnav read the same ( +- half mph ish ).

What size are your tyres?

In terms of your Venice trip, how many miles by satnav? If you know that you could convert to Kms
then see which is closer to the bongo odo reading of 979.

Someone will probably be along with a good way to work it out- links to tyre size conversion calculators etc.

James
Yes, I understand where your comming from, your talking about the rolling circumference of the tyre from one point to another I havent checked this yet, im running 220/55/17 rears, Im more interested if its true that I can move the speedo needle.

Re: speedo oddmeter inaccurate

Posted: Fri Sep 30, 2011 7:52 pm
by teenmal
mentaliss wrote:
skater wrote:One thing to consider/check:

When my rear tyres were standard size ie 215/65/15 my speedo read 60mph
but the satnav said 56mph.

I now have 225/70/15 on the back and the speedo and satnav read the same ( +- half mph ish ).

What size are your tyres?

In terms of your Venice trip, how many miles by satnav? If you know that you could convert to Kms
then see which is closer to the bongo odo reading of 979.

Someone will probably be along with a good way to work it out- links to tyre size conversion calculators etc.

James
Yes, I understand where your comming from, your talking about the rolling circumference of the tyre from one point to another I havent checked this yet, im running 220/55/17 rears, Im more interested if its true that I can move the speedo needle.


Hi the needle can be moved,I would let your supplier do it for you as they suggested.

Re: speedo oddmeter inaccurate

Posted: Fri Sep 30, 2011 8:20 pm
by briwy
Even if you sort out the needle you have obviously got a problem as you say with the odometer, unless Venice has been moved.

One way round it is to fit a speedo from a Mazda petrol car. cant remember which one, may be an old Mazda 3. These have a reference GA5 on the dial and both the speedo and odometer read in miles.

If you ask around someone may have one.

Re: speedo oddmeter inaccurate

Posted: Fri Sep 30, 2011 10:30 pm
by dave_aber
The one you need is a GA5R speedo from a Mazda 626 of around 1991 age. Direct replacement, and will read distance & speed accurately on the correct size wheels

Re: speedo oddmeter inaccurate

Posted: Sat Oct 01, 2011 2:26 pm
by mentaliss
dave_aber wrote:The one you need is a GA5R speedo from a Mazda 626 of around 1991 age. Direct replacement, and will read distance & speed accurately on the correct size wheels


thanks pepole for you help.

Re: speedo oddmeter inaccurate

Posted: Sun Oct 02, 2011 10:43 am
by maxheadroom

Re: speedo oddmeter inaccurate

Posted: Sun Oct 02, 2011 11:14 am
by teenmal
This place is always worth a look for s/h bits.



http://www.u-pull-it.co.uk/info.html?vi ... tPricelist

Cheers.