2019 RAM 5.7l 2wd with 3.21 non posi and no eTorque highway 19.5 to 23 on 88 octane (mid grade) only $0.20 gallon more than 86 octane (read the manual).
I have been running 89 since the odo said 873 miles. So, the last more-than-6000 miles.
I realize that my scenario is probably just about worst-case. I work from home, so no commute. I live right in the middle of a very urban area. So, everywhere I go is generally within a mile, maybe 2, and it's all stop-and-go. OR, it's a road trip and I'm on congested Interstate highways with the adaptive cruise set at 80. That means lots of slowing down from 80 and then speeding back up.
I wouldn't mind the mileage so much if the overall engine performance didn't feel JUST like the Hemi in my previous truck (an '09 RAM 1500). That is actually the reason I didn't buy a new truck sooner. I drove a '19 when they first came out. Engine-wise, it felt just like driving the truck I already had - which is okay, but it's certainly not fast or even a top performer in the class. I really wanted to hold out for either the new EcoDiesel or an option for a bigger, faster Hemi, like the 6.4L or possibly a supercharged version.
I finally bit and got a new truck because, one, it was 26% off MSRP AND they gave me a more-than-fair trade-in value on my '09, and, two, my '09 was in the shop 3 times, for a combined total of about 6 weeks, in the 8 months or so prior to getting the new truck. It was under warranty, so it wasn't really costing me anything - except time and aggravation, and I got tired of that!
My new truck has been in the shop for a week and a half now, getting the bumper and tailgate replaced from where I backed into a pole (dumbass!!). I've had an F150 XLT Crew Cab as a rental. I'm not positive, but I think it has the 2.7 EB. At first I didn't like it because it's a very basic trim level. None of the bells and whistles like I have on my RAM. But, the engine has really grown on me. It doesn't SOUND like a V8, but I think it actually drives a lot nicer than my Hemi. And especially so if I put it in Sport mode (which I have only bothered with 2 or 3 times). The Hemi is not gutless, but compared to this EB, it kinda feels that way. With the EB, you can just tip into the throttle to accelerate (say, to pass a car) and it goes. With the Hemi, it usually has to downshift at least one gear before it really pulls. The Hemi pulls good and sounds badass when I mat the pedal - but I just don't do that very often. Normal acceleration from a light, or non-full throttle acceleration to pass somebody is something a do WAY, WAAYY more often. And for that, the EB is nicer-driving.
Engine aside, I think the RAM is better in every way, so I will not be jumping back to Ford (which is all I had before '09). But, if the RAM had an option for a motor just like the Raptor has, I probably would be in line for a trade-in.