FWIW - the recommended rim width for a 165/80/15 is 4 - 5.5".
https://www.tirerack.com/tires/tires...omCompare1=yes
Personally, I'd go with the 205/75/15 as the 165/80/15, besides being very skinny, is only 25.4" tall. The tread width on the bigger tire is very similar and the tire height is 27". Recommended rim width is 5 - 7".
https://www.tirerack.com/tires/tires...omCompare1=yes