Hello all,

Just got back from a 500 mile round trip. Portland to Seattle and back. 19.65 mpg. That's hand caculated. Overhead was reading between 20 and 21.9 the entire trip. I was surprised it was reading that close. But.... I think I figured out how tomanipulate the overhead reading. When I first got the truck,I noticed when driving, like on the freeway with cruise controll set, and you hit the reset button a few times. It bumps the mpg's way up, and tends to stay there for quite a few miles. I've had mine reading 28mph for 20 plus miles (this was when I first got the truck) . I'm wondering if this is why some peoples overhead happy meter is always way off?I have not hit the reset button on mine for an entire tank of fuel, and it seemed pretty close to hand calculation. Maybe it will get even closer this tank if I keep myhands off that reset button?

This was with speeds between 60-65mph.Notmaking any landspeed records by any means, but I see no reason to go any faster. 2007,5.9 auto. quad cab short bed, 4x4. I only have 1400 miles on it. Hopefully it goes up a little bit when broken in.

Anyway, just thougth I would share.

 

That is good mileage I will be making the same trip tuesday.

 

I recently drove from Dayton Washington to just South of Provo Utah on my way back to Texas. That stretchwas 654 miles I put in 31 gallons of fuel when the low fuel light came on, that makes 21 MPG not to bad! I ran 5 MPH over the posted speed limits 70 in Oregon and 80 in Idaho and Utah.

 

In Trailer Boat mag. (Aug. 2007) they did a test on a 2007 2500 CTD Mega Cab 4WD, 3.73 gears while towing a 26' Searay boat.Their test result shows Overall nontowing MPG at12.7 andtowing at 8.8mpg. I have a 06 CTD2500 2WD and tow a 26' Formula, which I would say the weight is close, and get around 17mpg highway 12.5 towing. Last month I towedour boat to Seattle from Ventura, Ca., 1300 miles. This month I bring it back after the Seafair Hydro boat races.

Is there really that much difference between the 5.9CTD's and the 6.7CTD's or are they feeding us the worst scenario?

 

It sounds like milage with these engines is all over the place. I drive like a grandpa, so that help me i'm sure. I think the 6.7 will average a litltle bit lower milage, but not much. I am courious to know what RPM's the 6.7 is turing at say 65 mph, with the 6 spd auto, compared to the 5.9 with auto. Anybody.

 

al5608,

What helped you get such good fuel mileage is that you drove between 60-65 MPH. Any time I drive between 55-63 I can get up to 21 mpg and once I go drive 64 or higher I know my fuel mileage will start to drop due to the higher speed and wind drag. I think most people could get beter mpg from there CTD if they just drove slower, kept the engine under 1850 RPM's and also used the TQ and not the HP of the engine.

 

Yes, I think you nailed it. I am noticing once you get RPM's up there around 2000, the milage goes down quite a bit. I hope I can squeek out a couple more miles per gallon once it get's broken it.

 

I just ran 5600 milesfrom Seattle to the Kenai Peninsula in Alaska and back with my 06 Ram 3500 4X4 carrying an 11 1/2 ft Lance camper and a load of gear including a top rack and a coffin box. I drove 65-70 on all the roads allowing that speed on the way and averaged about 11 mpg.
On the return trip I took the back roads through Chicken and Dawson anddown to Hyder on the Coast returning through Whistler, B.C.carrying an estimated 500 extra lbs of gear and 4 large square boxes and an bicycle on top. Probably averaged about 40 to 45 over the mountain passes and kept the top speed down to 62 mph on the highways. Averaged 13.8 if I throw out one tank of fuel that was bad. I only got about 8 mpg out of that tank.That tankalsodemonstratesthe quality difference of fuelsfrom even the name brand suppliers.
Engine rpm's may have something to do with the difference but air resistance increases as the cube of velocity.

 

On my overhead, it is pretty close, as you said. I think the big jumps when hitting reset on the highway are caused by not having to be on the throttle, you having already reached "Cruising altitude", then it slowly works down, but not nearly as slow as it works up from burning all that fuel on the takeoff / on ramps, etc. I have to re-calculate mine, as Bullydog has not released the program to re-calibrate the system to report for th tire change, but still pretty close to actual.

 

Man I am sorry you even had to come close to happy valley "Provo Utah"[sm=badbadbad.gif]Anyways I have got into the 23mpg range driving about 60mph on a 120mile round trip to Salt Lake City and back. Not very fun driving like a grandpa but it saves me $$, that is hand calculated mpg.