Would you put 13" slicks on 10" rims?

Assumed that the wheels on my 31.0x13x15 slicks were 12" wide, but discovered they are 15x10. Do you see anything wrong with a 13" wide slick on a 10" rim?
Tried my friends 12" wide rims (same backspacing) with my tires but they rub in the fender wells. Would like to keep stock fenders.