OK, I've owned this '03 Ram for about two months now. It's a QC/LB 4x4 with the 48RE auto and 3.73's...HO CTD. It has 9500 miles on the odometer. Up until now, my driving has only been around town with the milage hand calculating out to be between 14.7 to 16.4 mpg.

Just this weekend I had the truck out for it's first drive of any long distance. I checked the overhead computer on the way down and it stopped climbing at 19.8 mpg over a little over 3 hour drive. I believe the drive was between 150 to 175 miles distance. We then drove some short trips for the next two days which dropped the overhead reading to 18.3 mpg. On the return trip the overhead maxed out at 19.0 mpg.

The fuel gauge was sitting at just a tad below 1/2 tank with 413.4 miles on the odometer. On fillup, the tank took 19.5 gallons topping off as close as possible to the previous fillup (estimate to be approx +/- 1 gallon).

That hand calculates out to be 21.2 mpg . I had expect to see maybe 18-19 highway mpg, but not 21 .

I know my calculations are right, but it still doesn't seem realistic for a truck that gets "average" in town milage and isn't even broken in fully yet.

 

Diesels should get better milage as they break get driven more.
Most new diesels start off with poor milage and gradually increase mpg as the engine seats in.

I average 17 around town and 20 on the open hi-way.
Enjoy.


Rich

 

10sec my overhead has gradually gotten to where it reads lower than actual.

Last weekend I went to Spokane (150 miles) with the cruise set at 78mph, my overhead read 19.7 MPG. I then did a bunch of driving around Spokane over the weekend, then Sunday drove home with the cruise at 75mph and the overhead showed 20.4. I filled up yesterday and had a total of 480 miles on the tank and hand-calculated at 20.8. I was quite pleased with this considering about 30% of the tank was running around town and highway was 75mph and above. Not only that I romped on it a couple times and hit 95mph.

Vaughn

 

With 22,000 miles, I get 18.5-18.9mpg intown driving and 23.5mpg on the highway(at 65mph with cruise control). These are all hand calculated. Before breakin, the mileage was about 3mpg less.

 

I've pretty much accepted the fact of the around town milage.

What didn't jive with me was the 21 mpg highway for a 4x4 that isn't completely broken in yet. That seemed more like a 2 wheel drive truck milage.

BTW, the truck was driven on the trip with the cruise control set at 65 mph with the A/C on the whole trip.

 

You'll notice that the A/C doesn't affect mileage or power as much as it did any previous gasser you've owned.

It affects, just not near as much.

65 seems to be the sweet spot speed wise, after that mpg drops pretty fast.
I wonder if they did that on purpose?


phox

 

That sounds about right! More highway and it gets even better!

 

i continue to be envious. iget 12-13 empty around town--10-11 pulling an emty 40 foot gooseneck trailer (about 2000 lbs) and 6-8 with 4 horse carriages on the trailer (about 5000 lbs) but lots of wind resistance .
will scwirm with the milage cause i love the truck but a little mileage would make things a lot nicer

 

Thats about what I get on my 03. It has nearly 18K on it now. I can get 24mpg on the road if I stay below 74 mph. Get above that and I get 21. Get around 80 and it drops to 16. They are real touchy. You need to experiment with speeds, over long distances, to find which is best for your purpose. One mile an hour in these things can make a big difference.

Oh, forget the overhead computer. They are notoriously inaccurate. Mine is usually 3mpg off.

 

I just completed a cross country trip last week and had a chance to check my MPG. I was not towing anything, I had no load, and I was the only person in the vehicle. All MPG calculations were by hand and I filled the fuel tank to the top of the neck (took a lot of patience and squeezing). BTW the cheapest diesel I purchased was $1.49/gal in Kentucky.

This was all freeway driving. I set the cruise control on 1850 rpm which is about 63-65 mph in 6th gear.

I ran the first tank from full until the low fuel lamp came on:

752 miles, 29.429 gals = 25.55 MPG

The second run was intentionally a shorter distance but again filled to the brim at start and finish:

312 miles, 11.806 gals = 26.43 MPG

The third run was as above:

469 miles, 16.321 gals = 28.73 MPG

Yes, I'm very pleased!

 

Jonesboro, great fuel mileage. Mine is very similar to yours. I never posted it before because it was a little higher than others and you always get the questions on "how did you fill up," was this computer mileage," "why did you drive so slow".
As you can see, mine is the SO 2WD-I also have the TAG, 4" exhaust and volumizer.

If you slow down to 55 on the country roads, you"ll have to stop and let some fuel out of the tank, it seems to overfill itself. Just kidding, but it will get even higher at 55, but I can't sem to go that speed.

 

fanofthewolf,

I was also a little reluctant to post my MPG numbers because I know many of the 600 owners are struggling with low MPG issues and I didn't want to sound like I was gloating. I have a lot of sympathy for what the 600 owners are going through and I wish the best for them. I feel my MPG numbers may give them some hope knowing that the only real differences that can explain the MPG dropoff between my 555 and an equivalent 600 is ECU programming.

 

Don't feel bad for all of us 600 owners, some of us (like me) are getting a consistent 16-18 mpg (last tank at 17.1, all in town)around town and over 20 on the highway unloaded. I just pulled 10k up the Alaska Highway from Wisconsin and averaged almost 12 mpg over the entire trip. All calculations done by hand, although the overhead has never been more than 1.5 mpg off either way (surprising). My 600 is one phenomenal engine, the truck as a whole is absolutely priceless.

Bert

 

Check my info at the bottom: I get 19.5 around town and 21 on the highway, On diesel #2. 50/50 #1&2 blend- chop 2 mpg off that. And I have a pretty heavy right foot. -Steve