Minimum tire speed rating for 92 LSL stock wheels?

Hi all,
After trawling the archives I couldn't find any mention of speed ratings recommended. Obviously the higher the better

However, some shops refuse to fit tires if they don't meet the minimum speed rating for the car, e.g. Costco.

I know the stock tire is the Bridgestone Potenza RE75 does anyone know what the speed rating on that is so I can use it as a minimum guideline?

Called my local dealership and they just scratched their head

thanks

Rich