I have a 2017 Australian Mazda 3 (BN) imported to the UK. Just like a UK model, it is possible to change the units used on the satnav and trip computer from km to miles and from litres to gallons using the menus. Unlike a UK model it does not have a button above the tachometer to switch the speed readout from km/h to mph. This meant that the importer wired a cheap Chinese speedo where the head-up display was. This is glaring bright green and not dimmable. It is less than ideal. The cruise control also reads in km/h.

I'd like to remove the Chinese speedo if I can find an affordable way to make the car dash read mph.

The tech at my local Mazda dealer says there is no way to switch the car systems to mph using the dealer diagnostic software.

Does anyone here have any idea if/how it could be done, either via a software change or some (maybe secondhand) parts?

Thanks