EM406 speed output in MPH?

I was wondering if its possible to change the output of the speed in the GPVTG string to MPH rather than KPH? I can’t find anything about it but I wondered why a field would be needed for the units if not. It would save me the job of doing it on my microcontroller.

If not does anyone have a code snippet in MASM to do the conversion to 1 d.p.? :smiley:

Thanks.