Here ya go, a little unbiased.
https://news.pickuptrucks.com/2019/12/2020-ram-1500-ecodiesel-mpg-report-after-900-miles.htmlThe MPG Results
Over the 901.7-mile round trip, unloaded, the Ram used 36.112 gallons of diesel fuel for a calculated average of 25.0 mpg. The truck's trip computer showed an average of 23.8 mpg, which was surprisingly lower than our observed mpg for this test. Both figures, however, fell short of the EcoDiesel's highway number, which was disappointing considering that the route was composed of nearly all highway miles. There are a few reasons that might explain this.
The 900 miles weren't flat and came with a lot of elevation change, from Los Angeles at sea level to Zion at 3,000 feet above sea level, plus you have climb over mountains to get there. Additionally, though the truck didn't keep track of average speed, it would have been quite high for this route considering raised speed limits in parts of Arizona and Utah where the Ram just isn't as efficient above 70 mph.
I would be remiss to conclude without mentioning that a gussied-up Ram 1500 Longhorn with the diesel engine is a near perfect companion for a long road trip. The interior is fantastic and comfortable, and with the 33-gallon tank I did about 600 miles on the first tank alone and could have gone farther. And, it is quiet. There's some diesel growl when accelerating, but while cruising the noise vanishes and the cabin is impressively serene for a pickup. The EcoDiesel may not have reached its lofty EPA fuel economy estimate in my test, but it certainly made a big fan out of me.
