I'd like to chime in on this ...
I recently drove from Houston, TX. to Modesto, CA. x 2
it's about 1900 miles (each way)
2011
6.2L
36gal tank
TRIP 2:
I have (had) 180,584.4k miles on my raptor (this was about 500 miles outside of Houston and at my 1st major gas up.)
I drove speed limit + 5mph Cruise Control. (Unless it was a construction zone or area of heavy traffic, which was rare)
I would only use 87
IF YOU'RE CURIOUS:
In the state of Texas, filling up from 37 mi to E it cost me about 65 bucks ... I think the price was 1.38 or something like that. I still have the receipt, just need to find it. But I'm pretty sure it is about as much. I'll look for it If you really want to see it. In Cali I filled up, at most I think was 103 or so. I didn't drive around in my truck while in Cali ... I used my brothers car hehe
As I pulled into this gas station, my MPG was at 15.0 AVG MPG.
I will say, that on the high side I got between 14.5 - 15. On the low side around 12.5 - 13.5
And I was sort of ******** bricks at this point because I was kind of out in the cuts, it was more like a Highway I was on, and not an Interstate.
I would be able to drive around 9 Hrs till my MPG would get to 50 miles remaining.
I did take a photo of my cluster as I pulled in to the pump. Soon as I figure out how to add the photo I will do so.
Other Things:
I purchased my truck used, it had 166k miles on it. The previous owner didn't really take care of it ... felt like the truck was totally disrespected.
The truck had a K & N CAI ... but I had to order replacement parts to get it back up to the way it was supposed to be.
I did the following so far:
new shocks and struts
new spark plugs
new tires
Oil Separator (this thing is nuts! I'm glad I got this.)
Changed fluids (oil, coolant, steering, tranny, brake)
Brakes (rotors and pads)
The tires & Oil Separator I did not add till recently (Less than a month ago), I made both trips on the old tires. I will be having another trip in October. If there is anything you would like me to keep note of let me know. Or a fuel additive that you want me to try out, I'm down.
Also, I didn't use AC most of the time. I'm from Cali and I like having my windows down and my arm out =)
I did however, use the AC when going through Arizona ... it hit 117 on my way to Cali. I didn't notice much of a MPG dip if any.
I will say that I really enjoyed the drive in my truck ... There is so much space, and its very comfy. I did sleep in NM at a WELL lit truck stop. I slept like a baby on the back seats!