My 2019 Big Horn 1500 4X4 (3.92) is only at 109 miles and 14.8mpg 5.7 Hemi non etorque 89 octane fuel. That being said, I have had 12,13,15,and 16 Ram 1500's with similar specs except they were all 3.21 rears.... I got 19.6 all around driving in the summer, 16.4 in the winter on my 16... the others were similar... I could easily hit 27mpg on the highway with no trailer and 70 mph+...
All of them got a couple mpg better after I hit 24,000 miles or so... if I ran 87 octane, I got about 2-3 mpg less than the 89 octane. Winter blend had the same effect on mpg. I am a retired ASE Master Certified Auto Tech with over 32 years under my belt. I seen this over and over hundreds of times with customer cars as well... nice change in mpg from 87 to 89 but not as much of a change from 89 to 93.
The feds say they have to run on 87, they didnt say they had to be at optimal performance on 87. There is a big difference, between running and running well.
20 cents a galllon difference is nothing to complain about. Thats only 5.20 on a 26 gallon tank and how many people run the tank dry...so its less than 5 bucks per fill up and for the performance/mpg boost I have personally had with mine.
That adds about 78 miles to the tank. now using the cost of the gas per gallon at 3.35, that 5.20 you saved wouldnt even buy you 2 gallons of 87 (3.15) gas. those 2 gallons at 19.6 would barely get you 40 more miles. I will still go farther on the 89 octane than the 87 octane.
this was figured at 3mpg better, but even 2mpg better still comes out at 52 more miles per tank with the 89
