Just finished a trip, most of it was Interstate Highway, 65-75mph, <10% was city
date odom miles gallons mpg lie-o-meter
6-7 53548 0 full
6-7 53913 365 20.45 17.8 18.2
6-10 54259 346 21.25 16.2 16.2
6-11 54692 433 23.88 18.0 16.4
6-13 55073 381 20.52 18.5 16.7
Total 1525 86.1 17.7 16.7
Tires aired up to spec, about 800lbs in the back, 3 kids 2 adults in the cab.
I only have about 5000 mils on the truck(2019 Cummins P4X), but I am pleased with the results I'm getting so far. The 212 mile was mostly interstate with cruise set between 72 and 4(I have found that my speedo reads 2 mph high) while the 27 mile trip was from DC back down home the other night after getting pictures of the memorial light at the Pentagon.
Break in was done with 25, 50 pound bags of sand in the bed and not treating her gently for the first 4000 miles. Sand is now out and she runs nicely.
I just hit my personal best of 20.9 in my 2016 XD PR diesel with just a bit over 58k on the odometer. It was after a fill up and driving from Williamsburg, VA to Chesapeake VA. Trip was ~55 mostly Interstate miles with slight rolling hills in Williamsburg to mostly flat for majority of trip. I had the cruise control set at 64 mph. I HATED having everyone blasting past me, but I was on a mission to see what mpg I could get since my typical daily commute is ~30 miles inter-city Interstate with some back roads/stop and go where I am lucky to get 18 - 19 average mpg per trip.
I’ve said it time and time again. If you drive like a gray/blue haired grandma you can get good mileage. If you drive like me...not so much. Mine has gone to about 15.5-16 on the interstate at 77-80. That’s with the topper and 295/70-18’s. I’m pretty sure it was better before the topper. Thinking I’m going to do an experiment and take it off for a few weeks and see if there is a big difference.
Its stupid and I didn’t buy it for mileage, but I’ve seen 17-18 at those speeds before and for the life of me I can’t figure out why it’s dropped. Maybe the tune, maybe the heavier Ridge Grapplers as opposed to the BFG’s, maybe the topper, or maybe it’s just my bad luck. I should just put black tape over the mpg’s and quit looking at it!
Very true. I have Ridge Grapplers on mine too and I'm sure they don't help much with the mpg. I admit when I first bought it, I was obsessed with the mpg and very saddened when I saw what the reported average was before I bought it. But I still loved the truck, especially after the test drive, so I bought it anyway. I have slowly accepted the fact that I am burning through $200+ a month in fuel regardless of whether I drive like a blue-haired old bitty or a white-knuckled ricer.
I unfortunately drive fast on the interstate, which leads to sub par mileage. Not terrible but I wish it was better. You have to pay to play though. If mine was stock it might be better...but I WON’T ever have anything that’s stock!