I seriously have a hard time believing the 20+ mpg claims.

I drove my Dmax at 65 mph max for 4 years and 80k miles. Average was 16.0 mpg.

My current 2007 Dodge is 2wd and completely stock. At 15,700 miles my current average is 16.5 mpg. Never over 65 mph! I commute 80 miles per day (65% hwy, 35% city) and would love to break 18 mpg hand calculated.

BTW, the worthless mileage computer reads 19.5-20.5 mpg.

 

If you read the quotes of the 20+ mpg claims on this post. Please note the guy is driving an 03. More than likely he has the SO 235/250hp and does 55-60 mph to 60 on highway and lives in the midwest with no hills in site. If you want better fuel mileage out of a 04.5. First get a cold air box second get a Quadzilla 2 xzt. I owned an Edge and Bully Dog neither gave better fuel mileage like my old Quad xzt. So I just got a quadzilla 2 xzt that can be programed to be a mileage max box also. But I think I get the best mPG out of the quad is the throtle response. So more power at lower rpms just seems to help me stretch out MPG's. I personally wont claim 20+ But with my old quad box I was getting 17-18 on avg with out it was 15-16.

 

I posted this response on another thread and think it applies here also. Something I never see addressed here is the fact that these engines seldom run at high enough engine temp. this causes mpg problems, mainly from low combustion temps. I wish someone would come up with 2 things: 1) An aftercooler bypass. 2) Automatic radiator shutters. I recomend covering the radiator not the front grill. I work mine a fair amount and can keep radiator fully covered til 40F. Even in the summer time my engine rarely gets to 200F. Keep these at a temp beween 200 - 220F you will see better fuel economy. If Auto Tans equiped be sure to keep cooler unblocked.

 

In response to the engine temperature, when I was searching for a diesel truck, I had spent a lot of time on the Ford Powerstroke Forum for information. The one thing I remembered in members post was the 210F thermostat. If I remember correctly, guys would replace their stock thermostat's for a slightly higher temperature one. I will go over to the ford site and ask one of the members what the 210F means in their profile and what it does for them.

SAS

 

I tried finding my Ford Powerstroke Forum, but was unable to find the one that I used to go to. I thought I had it in my favorites, but I see that I do not (I do have the DTR forum in my favorites.

I will keep looking for the ford forum to ask the question on why the blue oval boys install slightly higher temp thermostats.

I wonder if we could do that but fool the electric fan to only kick on when it is 10 degrees hotter than the thermostat otherwise I am assuming the fan would want to always cool if we put in a 210F thermostat.

 

I just drove 673.1 miles on 32.11 gal. 675.1/31.21 = 21.566. Edge on level 1. Sorry, don't be haters.

For those of you getting less than 15mpg - Drive with the wind to your back all the time. To get home wait for the wind to change direction.

For those getting less than 14mpg. Change your air filter and fluids.

For those getting less than 13mpg. Bring your truck back to stock.

For those getting less than 12mpg. Get a new truck

20 + is possible

 

My driving daily commute is 70 miles round trip. 60% at 55-60 mph, 5% in town, and 35% at 65-70 mph.. I have never gotten below 17 mpg with averages at 19-20 mpg by hand with the OH reading 22-25. I drive in pretty mountainous terrain too. I always try to keep RPM's while shifting below 2500 and use cruise consistently.

 

I live just outside of Detroit. Last summer we went to the U.P. We left with a full tank. I filled back up just before crossing the bridge. It was 300+ miles one way. With my wife & I and our three kids in the truck plus crap in the bed which has a cap.......we averaged 19.97 mpg on paper at about 73 mph.

 

2006 mega cab- im getting anywhere's from 15 to 18- when i put the snow plow on or pull my 30' tag along i get approx 13mpg-i have never gotten anything higher than 19 on a trip- any sugestions on how to get mileage in the 20's would be great- i never beat on the truck- i have a 6speed manual tranny- no aftermarket items at all-

 

My 03 (HO, 4:10s) is getting 15 mpg highway and 10 mpg stop&go (not city though). Ugly! I'm replacing the fuel filter tomorrow (just in case) and from there, I don't know what to do... other than go to the dealer... they just replaced all six sticks awhile ago, which made it not smoke white (etc) but the mileage dropped even more....

 

With 4.10s unless you have big tires or the 6th gear is more overdriven that I think you will have to slow down.

I get my best mileage vs. time on road at about 63mph by my gps.

And I have 3.5x rear ( and 2WD ).

Oh yeah, if 4x4 I think manual hubs to stop all those joints from spinning would be worth it.

 

I hear you dave. The funny thing is, most of my stop & go driving is at 45-50 mph (top) and the highway has been at 60-63 mph (top) -- all per my GPS. I have slightly wider tires (can't remember if they are 245 or 265) but they are the same height as stock... and the only other thing that I've "done" to the truck is put a camper shell on it....

Point is, I don't think speed is a factor in this case, and I'm taking it pretty easy on the throttle and shifting early (keeping it below 1900 rpm 99.9999% of the time) OK, so that's an estimate

 

Then I just don't know! I drug our 350 gallon tank trailer some 20 miles full and the same empty today.

I had a pretty long running avg on the overhead and managed not to lose even a tenth.

I keep telling my "people" ( family, boss etc. ) that I couldn't stand to wreck this truck.

I think it just might not be replaceable!

Again I do the best at 1800rpm and 63mph (according to two GPS!)