Best speed for mpg

[alow]

I'm finally getting around to a road trip and wondering if anyone has seen a good top speed to get the best mpg? Lots of 70 and 80 mph zones.

Also I read somewhere that eco doesn't kick on over 70. Is that a real thing?

 

[hotrod45]

My truck likes secondary roads the best, 50-60 mph. Over 60, it'll drop off slightly and get around 18.5 mpg at 65. Every couple miles per hour over that will result in the loss of a tenth or two.

 

[Neil E]

55 mpg is the best for MPG's, I have found. But for safety reason, I usually don't drive more than 5 mph less than the speed limit. I'm lucky, my commute has speed limits ranging from 55 to 65 (though it is 70 for a short 5 miles).

 

[hotrod45]

55 mpg is the best for MPG's, I have found. But for safety reason, I usually don't drive more than 5 mph less than the speed limit. I'm lucky, my commute has speed limits ranging from 55 to 65 (though it is 70 for a short 5 miles).

Good point. I try to set the cruise control on limited access highways so that my speed doesn't drop off more than two mph below the speed limit on grades. Speaking of which, the 8-speed transmission is far superior in that regard compared to the 6-speed. On Interstate 91 in VT, it's up/down all the way and I set the CC at 68 so people don't start doing crazy things near me going up grades. Set at 68, the truck will usually stay at 65 (posted) going uphill.

 

[McBroom]

63-68 in my HD with 3.73’s


I Love my 18 Ram 2500HD 4x4 CC
Blue Streak Pearl off-road

 

[Diugc]

Just drove my 2009 Ram 1500 Laramie 4x4 from FL to Cali through I10 with cruise control at 75-80 and average 17 mpg

 

[John813]

With the 3.21s on Florida terrain I get 20-23 mpg from 80-83mph.
Of course headwind will knock it down a smidge.

 

[alow]

Sweet I'll report back when we get back from the trip. I'm running 3.21 but I have the off road PKG so no active air dam. Plenty of mountains so that might effect it too but it's about 3k mi so there should be some flats in there somewhere.

 

[alow]

I found that I can sit around 20-23 in the flat as long as there was no headwind. In a headwind I was getting about 16. It didnt seem to matter as far as speed as long as whatever speed I was going kept my revs low. Hope that makes sense. Eco kicked in mostly in long flats or obviously downhill.

 

[Denis]

I have 21-22 mpg at 60-65 with 3.92 gears. I think with 3.21 it's around 70-75 mph.

 

[Gondul]

Ran up from FL to WI.

75mph with cruise control
Average was 15mpg
Best was 16mpg
Worst was 14mpg

 

[adrianp89]

Headwind kills it. Coming across a bridge twice every day really knocks it down, it shoots up when I get onto some solid land.