You might want to check your figures. https://www.mitsubishi-motors.ca/en/...s/mirage/specs The important number is the GVWR which AFAIK doesn't vary much more than a few kgs between markets, if even that. The GVWR is somewhere in the 2950 lb. range and since the Mirage weighs 2000lbs. you have a total cargo capacity of about 950lb. Subtracting the 600 lb. total load including my light aluminum trailer then removing me @150 lb. and there's still 200 lb. of GVWR available. Well within safe limits.
Yes, tire sizes vary considerably among models. But AFAIK the GVWR is still the same even for the skinny tire models.