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can i get 23MPG?

6K views 62 replies 33 participants last post by  johnmbailey 
#1 ·
i am buying the new truck to replace my 6.5 and to use for a long over the road job. can i get 23MPG at 65MPH? or are those pillow dreams? i plan on running it on home heating oil so that should help MPG wise as well as giving the necessary sulfur so all opinions are valued. if i cant grab 22-23 on the highway then i cant own this truck.... what do you think.
no plans for bigger tires or a lift. will have a bullydog in the first week thou. 6sp 06.
 
#2 ·
you can get 22 - 23 mpg if doing lots of downhill driving or if your reading the overhead lie-o-meter. there are claims of people getting those numbers tho... if i drove 55, no stopping on relative flat ground i could probably pull close to 21 - 21.5 i don't think your going to get better mpg with HHO, WVO or Bio
 
#3 ·
My personal opinion is that you will not achieve 23 mpg. My truck has a best mpg of a touch over 21. I have taken a couple of trips from SC to NJ and PA and average 19 - 20 for those trips. I'm sure someone will claim they are getting 23+ on the highway, and I'm not gonna call anyone out, but I have never been able to get that good in 93K miles of trying.

BTW, home heating oil is dyed red, and if you get dipped on the road it will cost WAY more than fuel.

Good luck with your quest.
 
#4 · (Edited)
Swap in some 3.55s in the back and you might get close...best I've ever gotten was a touch over 21 driving from San Antonio to OK at 60 mph (and prob w/ a good tailwind since I was going south to north).

Anyhow, 3.55s paried with maybe an MP-8 might get you close...but then you might run into injector issues running high pressures for long periods of time on the highway.

Also, get a 6-speed
 
#8 ·
on my recent trip to edmonton i was getting 9.5L/100km which converts to 25 mpg with my 2001. in the city ive been getting 20-22mpg. thats all hand calculated(dont have lie o meter). I was doing 115km/h which is 70mph
 
#9 ·
Not so much, the best I can get on a really good day doing between 55 and 65 is 21 mpg. Otherwise at 70 I'm lucky if I get 19 -18.
 
#10 ·
3rd cummins and 1 powerstroke, many a trip from Ak to TX (12 times). Only driving 50-55 have I ever got over 20 hand calculated. I flat out don't believe a consistent 22 or even 19 for that matter. Call me stubborn or just experience... from 4 diesels later and many a 100,000's of miles. By the way I do the math every time I fill up. I even put in neutral for the long 3-5 mile downhill coasts that I come upon. Still no 20-23, but the lie-o-meter always says 20-24mpg. Just my 10cents.
 
#12 ·
Looks like we are on the same planet. The funny thing about calculating fuel mileage is that if you don't fill the exact same way each time your mpg's are not accurate. What fun..., but I am always hoping that someday my truck will mysteriously get 21 real mpg's. I even get worse fuel mileage with my fiberglass camper shell on compared to off... wind drag i guess.
 
#13 ·
no you can get it in everday driving...i get 22 with mine (hand calculated) with everything i have and the airdog should add 1 or 2 mpg
 
#14 ·
Dream on you do not get that mileage with those mods.

No, you can't get that mileage. But you should still get the truck cause it's awesome.
 
#15 ·
Good looking truck dodgesmoke. Don't ever, ever, ever sell if you get that mileage with those big tires. You would never be happy again.
 
#16 ·
The only way you can see 23 is driving downhill on the highway unloaded with nobody in the truck and a good wind blowing at your back. I am on my 3rd cummins and the best i have seen anyware from stock to many different programmers and intakes is 19 on the highway unloaded keeping the rpms under 2k. My last mileage check on wednesday on my 06 driving around town was 14.8. You can believe what you want but out of all the people i talk to personally have Never seen 20!
 
#21 ·
Thank you for proving my point!
 
#22 ·
so if its a 2wd, 6 speed, on a lowering kit. and you can drive like a granny, maybe you can get 23. i just got 16 going from ann arbor michigan to fort wayne indiana, but that was doing 85 with the pmt on performance.

i think its possible. but if its a 4wd, forget it. 21 MAYBE 22 if your lightfooted and lower it 2 inches. jmo.
 
#23 ·
you guys must not be doing something right my hand call is 23.9 and od reads 24.7. and I have 35 inch tires. I guess my dreams are true
 
#25 ·
im not doubting you guys. i just havent had my truck long enough to take it on a nice long cruise. whenever i go somewhere, its flying, so i can belive its possible, i just havent seen it.
 
#28 ·
Hahaha you forgot to factor in the up part of the mountains, you can't just compute the coasting down!
 
#30 ·
WOAH!!! didnt mean to start a pissing match.
here is my curent stats.
i can pull 18 all day at 70 mph in my IDI 6.5 .....
but if i am not getting 22-23 why bother with a diesel at all? the new ford gassers are getting 21MPG... on cheaper fuel....

or maybe a SRT-10 truck, they get 12 mpg and i am sorry they look cooler then a diesel dodge.


am i wrong or did a truck magizine get 20MPG from a dodge diesel???????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????
 
#41 ·
Sorry but Fords do not get 21 mpg I don't care what their ad says.

i am about l---l this close to just getting a SRT10 and calling it a day. if i cant get the fuel mileage to use this for work i would rather have something that is fast and handles...
An SRT 10 is not a work truck. Sounds like you are confused about what you need the vehicle for. Also, enjoy your 8 mpg with that thing.

If your truely into getting good mpg, put a CNG (compressed natural gas) system on it. Can reach up to around 30 mpg! Also can see upwards of 100 hp gain!
30 MPG out of the diesel ok sure maybe. BUT, what is the cost of the needed parts, installation, refilling the gas, and how much inconvenience is it going to cause having to refil all the time? Does it ever pay itself off?
 
#31 ·
Ok. Here it is. You can call it B.S. or not. With my 05 with 37's on 3.73 gears, on the highway unloaded I have seen 23mpg's. Big tires lower gears, makes the engine work less. I turn only 1400 rpm's at 60mph and 2000 rpm's at 78mph, but only 16-18mpg' towing my 10k trailer. Now in town different story, 12-16 towing my 10k trailer in traffic 14-18 empty. I fill up at the same station 2 miles from my house and write in the milage everytime, date and gallons of fuel. On the highway empty I have seen the overhead lie-o-meter see 28 before. Everything is corrected to the larger tires. Now on the highway I turn to economy, and turn the timing up.
 
#59 ·
K.... i'll call it since you told me i could..... sounds like i need to put a lift kit and some bigger tires to increase my mpg....hahahaha
 
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