>On Sep 15, 6:48 pm, "Dr Zoidberg" drzoidberg.co.uk>
>wrote:

>> Cost.
>> There can be a fair few percent difference between all the different
>> wheel/tyre combinations on a particular car , especially when you take into
>> account old and new tyres and over and under inflation.

>
>Tyre inflation they can't do anything about , but for a car with
>correctly inflated tyres of the correct size I see no reason why the
>speedo can't be accurate.
>

>> To try and match all of these would require individually calibrated speedos
>> and periodic adjustment at a fair cost compared to "one size fits all" for
>> less money

>
>Why individually calibrated? Do you think they individually calibrate
>every RPM meter for every individual engine? If its electronic it'll
>just be a setting for whatever car its installed in.
>
>B2003