Grand Mesa
Senior Member
My son runs 285 75R18 (18 inch wheels) tires on his 2014 Ram 2500 Cummins diesel 4x4 which is a 35" tire and the same width as my 2016 Power Wagon's factory stock 33" tires. It's a good choice for going taller as it is with the 285 75R17 at 34". He said that the taller tires did not impact his mpg with his manual transmission and 3.42 gear ratio. It is still around 14 mpg (hand calculated based on GPS) with his nearly 5 ton in weight truck.
Going taller and not wider lowers the highway RPM especially in the 75, 80, and 85 mph (Texas) speed zones which should save some fuel with our 4.10 and 4.56 gear ratio Power Wagons. It's a heavier tire than the stock size and so that should have the opposite impact on the fuel mileage.
The 285 75R18 tire is somewhat fair in choice and availability. The plus is that it should have no rubbing issues with a stock Power Wagon due to it isn't any wider than the stock 285 70R17 size. Also, living in the snow country going any wider than a 285 width tire on unplowed mountain roads isn't my first choice. Tall and narrow tires is always the safest thing at least for me for winter driving.
My plans are to go with the 285 75R17 tires though in order to not cut my mpg from 17 plus on the Interstate and to not have to purchase some 18 inch wheels in order to run the 285 75R18 size. If some manufacturer made a 285 80R17 (35") sized tire that would be my choice.
Going taller and not wider lowers the highway RPM especially in the 75, 80, and 85 mph (Texas) speed zones which should save some fuel with our 4.10 and 4.56 gear ratio Power Wagons. It's a heavier tire than the stock size and so that should have the opposite impact on the fuel mileage.
The 285 75R18 tire is somewhat fair in choice and availability. The plus is that it should have no rubbing issues with a stock Power Wagon due to it isn't any wider than the stock 285 70R17 size. Also, living in the snow country going any wider than a 285 width tire on unplowed mountain roads isn't my first choice. Tall and narrow tires is always the safest thing at least for me for winter driving.
My plans are to go with the 285 75R17 tires though in order to not cut my mpg from 17 plus on the Interstate and to not have to purchase some 18 inch wheels in order to run the 285 75R18 size. If some manufacturer made a 285 80R17 (35") sized tire that would be my choice.