which of these two tires will give best mileage?
these are going on the back of my 2wd ranger.
205/75R15 overall dia. 27.1", weight- 21.6 llbs., rpm 767 or
215/75R15 overall dia. 27.7", weight- 23.8 llbs., rpm 750 the overall dia. of the stock tire is 27.4" would the slight increase in rpms of the smaller diameter tire be more than offset by the reduced weight and slightly smaller contact patch? thanks