Help! Does anyone have any ideas on a way to get decent fuel milage (10,000 miles getting 12.5 MPG) out of this new 600/325 hp engine? I am so upset that I got rid of my 2001 2500 245 Hp 6-speed Quad cab 4x4 that I could spit. Sure the new one is quiter, a TINY bit more back seat room, supposedly 325 Hp (I don't even notice), but I would rather have 17.5 MPG than 12.5. Does the new Edge chip help any? And what is the cheapest anyone has seen them priced at? THX

How are you calculating it?

If that's what you are truly getting stock, unloaded I'd be having it looked at.

I have the same truck and i was getting the same gas mileage until completed a 3000 mile tow job of 11000 LBS. You also have to consider your driving habits. I've discovered yor gas mileage is greatly effected my both throttle position and speed. Try reseting your mileage calculator while traveling between 55 and 65 mph on level ground. I was able to get around 17 mpg in those driving conditions when my truck had only 2000 miles but i know thats unrealistic. At around 5k i purchaced a magnflow muffler which was around $250, and a AFE cold air intake for around $300. Those two mods increased my mileage by around 2 mpg. Shortly after i moved from Idaho to Alaska towing a trailer with most of my houshold goods inside. On the way I got horrible gas mileage around 8.5 mpg but i was driving hard over mountains and I also wanted to break the engine in as much as possible. Now with around 9500 with the same driving habits as before i get 16-16.5 mpg and thats driving around Anchorage in heavy traffic. I ordered the Edge two days ago and I will post the results in a few weeks when I can tell all the effects

Is this with 3.73 or the 4.11 rear? Have to say I'll be pretty disappointed if I get under 15 unladen with the new truck.

I have the same truck and have not broken in yet. Here are my mileages so far. I check with calculator too as sometimes the trip display for mileage is off some and sometimes it's very good. Also I reset at each gas stop. Truck with 2k miles.


Unladen, 18 mpg. City only, 15. Towing 6k travel trailer 12 to 12 1/2.


I'm hoping after break in it will get better. http://www.dieselplace.com/forum/smileys/Approve.gif


Hawkster

But is this with the 3.73 or the 4.10? (oops, got it wrong earlier and thought it was a 4.11) I would think that would make a significant difference.

Trip computers do tend to be off, so it's better to go by the pumps. Then again, pumps lie as well, but usually they would lie in the sense of showing worse mileage than you actually have.

When I pick up my truck from Dallas next Friday I'll be driving it approximately 1500 unladen highway miles in the first 2 days of ownership. I'll make a point of jotting down miles and gallons and see what kind of mileage I can calculate. With my old 6.5 I used to get 19.6 if I cruised at a steady, level 75 mph, and about 16-17 when cruising at 80-85 or through hillier country. So, I'll post my mileage figures when I return.

I've got the 600 with the 48RE in a 4x4 2500. I don't pull a travel trailer over the mountains. I pull a 7k tool trailer in a lot of stop and go traffic. I have 7500 miles on the truck and get about 18.5-19 unloaded and 12-16 loaded. I fill up every 400 to 500 miles. I do have a heavy foot which leads to many 3/4 to full throttle starts. I love to feel the 600 pull and it does it well.

I had the SRW 4x4 with the auto and the 4:10s.. Now i have the Dually with the 6 speed. So far at 2000 miles and comparing both trucks the Auto got better.. Over 16 mpg sometimes. the manual dually is getting 14.6 mpg.. I would gladly trade the 20 extra horsepower and the 5 foot lbs of torque for mileage over the 17 mpg range....

Rumor alert....


STAR would have a recalibration out in October for these 600s that would fix the white smoke startup problem and get this,...increase fuel economy!!! it would be handled via a TSB and not a recall, so you'll have to request it.

Going to have to keep an eye out for that TSB. So far I've got just over 1600 miles on my truck (picked it up Friday). Almost highway, got 14.9 on the highway going 80-90 according to the trip computer. Noticed about 16 for slower driving (~60) around town with a little stop and go thrown in there. I imagine I could probably get 16.5 or so at this point if I cruised along at 70-75, but I was in a hurry to get home. http://www.dieselplace.com/forum/smileys/Big Smile.gif

Need to get it broke in before you will get the best ruel mileage, but if your only getting 12.5 dont expect to ever get too great. Ive heard on the older styles (24 valve) anywhere from 13 to 20.

I met a guy on my drive back with a '99 24-valve 1-ton dually. He claimed to get 22 with 220k on the clock.

sheetsp, I have almost the same exact truck as you. Mine has a 3.73 rear end, but I have 315/70/17 tires which negatively impact my mpg. Any way, 2 fillups ago, I got my best tank which was about 80% highway, 20% city and averaged 19.6 mpg. This was driving 60-65 mpg on the highway. Normally, %50/50 city/hwy I average around 17.5. My absolute worse tank was 16.5 just after I put on the 315's BFG over the Michelin 265's. I'm chalking that up to the computer having to relearning my driving style.


Now, if I drive 70-75 my mpg drops pretty dramatically and I'm in the high 15's low 16's. Driving styles are everything, and I've simply learned to slow down.


Upping horsepower/torque is gonna cost mpg, but I wouldn't think it would be 12.5 mpg. What build date engine do you have. If I remember correctly, mine is a 12/03

Shouldn't the 315/70/17s improve your mpg by being a slightly taller tire, or does the increased rolling resistance offset that?

Driving style really is everything, although I'm thinking that the revs are what really kill the mileage. If you think about it, 60-65 mph you're going under 2000 rpms, 70-75 mph you're a bit over 2000 rpms, and 80-85 (what I was cruising at on my long drive back) you're going about 2500 rpms. So, at 60-65 you're spinning about where the engine makes max torque (i.e. is most efficient).

Then again, you're also trying to move a brick wall down the road at a pretty high rate of speed, which I'm sure doesn't help things any.

Other question: What wheels did you put the 315/70/17s on? I hate the factory 265s and want to put on 315s, but I also don't want to buy new rims (I know, I'm cheap).

I took delivery of my 2004.5 CTD in April. I have gone from 14 to 20 MPG. I installed 315's at about 2500 miles. My milage has just gotten better.


My truck at www.GoRowan.com/2004ram (http://www.GoRowan.com/2004ram)


2004.5 CTD 48RE, 4x4, 4.10 LS


http://www.gorowan.com/2004ram/DSC_0965.jpg

Cumminz, I'm calling your bluff on that one. I have a 2004.5 2500 4x4 CTD 6 speed with BFG 315/70/17 AND a bed lid, purchased on March 31 of this year. I refuse to believe that an auto truck with 4.10 get better gas mileage than a manual transmission truck with 3.73, and on top of that went from 14mpg to 20 mpg. If in fact true, you now have the best gas mileage for a 4.10 auto truck that I have seen ANYWHERE on the net, and I do read alot of dodge/cummins forums daily. Are you driving 50 miles an hour on the highway? Please let us know your driving styles. Are you saying that you average 20 mpg? I had a one time best of 19.6 mpg, but I don't go telling everyone that my truck averages 19.6 mpg. Instead I tell that what I average in normal driving conditions, 17.5 mpg, not all highway miles. I see so many people who made 1 trip where they average 19 or 20 mpg and then tell everyone that their truck averages 20 mpg (not insinuating that you do this).


tdupuis, every account that I've read of the BFG have said they make a negative impact to the mpg. However, it appears to be small to none (few occasions). Largely because it is a big tire and rolling resistance is more than stock. On the highway, with my stock 265 and 3.73 gears, I was turning JUST under 2100 RPM at 70 (probably around 2060-2070). With the 315 I now turn around 1800 RPM on the highway, so there was a noticeable difference in RPM. This obviously has to help gas mileage due to less RPM, but I don't know if its enought to overcome the extra mass, width and rolling resistance of the bigger tires.


Most everyone mounts the BGF on the factory rim 8" rims. BFG recommends a 8.5" minimum wheel width for these tires, but the .5" hasn't been much of a concern to everyone. The jury is still out on if I like these tires. They make the truck look great, and offer plenty of ground clearance, but I'm having a devil of a time getting them to balance. Also, I do not tow anything. I've read some negative posts about people trying to tow heavy with them and having failure. After all, they are a D rated tire, and not E rated.


Also, you may/may not rub. Mine do rub when I have my wheels locked full right/left, and am going more than 10 mph. Edited by: djp9747

My milage,


My last post stands exactly the way I posted it. I have been leaving posts on 4 different sites since early April about my milage. The very first posts started out around 14mpg. The milage has crept up since then to a high of 20mph. The trip to the beach is from piedmont NC to coastal plain in beach of SC. Would you say that is roughly downhill mostly. Sea level has more oxygen, rocky mtns. has less. I did not say my average was 20. I said that one trip I got 20. The last several fillups I have been getting between 16.5 and 19.5. Depending how much I stood on the pedal. I ordered my truck with 4.10s knowing I was going to go to taller tires. With the combination of doing away with the cat and installing a straight thru muffler and high flow air filter I think I have about the best combination of good breathing CTD. I have made posts about the idea of 4.10 gears. I personally think that my truck with a locking torque converter and 4.10 gears IS the best combination for this new truck. The engine is NOT lugged down. I personally think the 3.73 gear is just on the verge of not enough gear to pull this truck at its best. Especially with the tall tires. If you keep factory tires I think it is a good gear.


One other thought. When my truck is running with the torque converter locked there is no difference in your manual in fifth gear with clutch engaged. Your sixth gear could very well throw your rpms to a point that you might be lugging your motor. OK, I know what you are thinking!! Get your truck up to 65-80mph. That is when the sixth speed is good and you are right. But guess what? Now you are fighting wind resistance that is great. Again maybe the CTD is at a rpm that is not just the best for the torque range.

Lugging your motor? I don't think that's possible with this thing, unless you get it down to below 500 rpms. Around town I shift at 2000 rpms with feathering the throttle, using 6th starting around 50 mph. Nope, no lugging over here that's for sure. Hell, start it in 3rd gear if you want, the motor couldn't care less. I have the 3.73 with the factory tires.

Thanks for the response djp. I was wondering if the weight rating on the BFGs might be an issue, and I really work my truck in terms of towing and hauling weight (having 2200-2300 lbs in the bed is not unheard of, nor towinga 7000-10000 lb trailer). At any rate, being the cheap guy that I am, I'm stuck with these Michelins (blegh... I hate Michelins) until they wear out. Seeing as I have 1700 miles on them, I suspect that may take a while.

ted, attached you will see pictures of my truck with the factory tires, and with the 315. You can see how much bigger they are.


Stock tires


http://www.dieselplace.com/forum/uploads/264_1850904-14-04_056-med.jpg


BFG 315


http://www.dieselplace.com/forum/uploads/D69_1850907-30-04_003-med.jpgEdited by: djp9747

Ted, one thing I just noticed from looking at another post. You have a 2WD. I'm not sure that you will have the clearance up front to be able to put on 315. Everyone who has them is putting them on 4x4's.

Since my last post, twice this week I drove roughly 40 miles one way to Concord, NC after filling up to the brim. I drove 127.3 miles at 65mph on interstate. When I got home I filled to brim again and used 6.066 gallons. My figures say 20.98mpg.


My truck at http://www.gorowan.com/2004ram


Later

CUMMINZ,


What does your computer say? I took a 04 2500 4X4 out for a test drive 2 days ago. I could not get the trip computer to say anything more than 10mpg on the freeway.


I know that there is a lot of talk about fuel economy. Some are getting good mileage and some bad. I know that driving habits has something to do with it but there seems to be some differences from truck to truck. I'm trying to figure out how accurate the computer is. If the computer said 15 or better on the freeway, I might have taken the truck home.


Lee Edited by: leesnuts

leesnuts, did you reset the trip computer? I not, there may have been a lot of idle time burning fuel while not moving from the lot...

I did reset the trip computer right before I got on the freeway. The dude was cool and let me drive it 14 miles. He told me that it should do 15 to 22mpg and when I only saw 10 I was turned off. He was kinda tricky also...switched it over to kpg which made it look better. Good thing I'm not a sucker.


From people's post it seems that the trip computer is accurate up to 1 to 2 mpg off. I wonder if the 2X4 would be better?


What I should have done was took another truck out and see the difference.


LeeEdited by: leesnuts

Actually, switching it to metric on the trip computer puts L/100 km. For that a lower number means BETTER mileage. If you were getting 10L / 100 kM that's really good... if I use metric most of the time it's in the 15-16 range. Pretty close to my MPG, despite completely different units! http://www.dieselplace.com/forum/smileys/Big Smile.gif

Yesterday I got a solid 20-21 mpg on-highway coming home from the NE GTG.

Mr Hoot,


I suppose that your 20-21 is hand calculated? If so, what does your computer say? That is exactly the milage that I am looking to get also.


Lee

No it's the computer but I did both before on the way to Thunder in Muncie and it was identical.

Thanks...I'll try another one to see if there is a difference. By my calculations your speedometer is 8.7% slower so instead of 60 miles, you actually drove 65.2miles. Which means that your mileage is even better.

My trip computer is about 2 mpg off!! I trust the pumps and calculate it.... usually about 18.3 mpg. This is pulling out of my drive hitting one stop light and then it's speedlimit 55 all the way to work with no other stops. So pretty much 100% highway. If I drive around town all day......well I won't go there because it's less than my Hemi!! http://www.dieselplace.com/forum/smileys/smiley7.gif But then I do that 100% throttle thing around town too!!! I wonder it that makes the difference????? http://www.dieselplace.com/forum/smileys/hihi.gif

I am sorry I have not been able to watch the posts here. I had open heart surgery about 2 weeks ago and I am back home now. They fixed 4 of my plumbing pipes going to my injection pump. It is amazing what our doctors can to now days. Back to my truck milage.


I learned a lesson many years ago from a friend in the drag racing circuit. He said to get your fuel into the motor quickly and efficiently and out the exhaust efficiently. I applied this theory to my CTD 2004.5 RAM. I installed a high flow air filter, a better exhaust, removed the converter, a high flow muffler, and a tornado. I have also often said that the CTD has a sweet point that it likes to run. When you drive don't spin tires getting to that sweet point but don't lollygag around getting there. Accelerate fairly sharply to your running speed. Then let your speed control take over. Find where your truck likes to cruise and stay there. Believe it or not, I have gotten my best milage when I pushed my truck. http://www.dieselplace.com/forum/smileys/smiley32.gif


My Truck at http://www.GoRowan.com/2004ram

Just installed the latest TSB at the dealership last week and gained 2.5-3 MPG. Got 7800 miles on the truck, still green, and getting 15-16 MPG now, instead of 12-13. With deisel up to $2.15/gal this was just in time. My comfort level with my new 600 Dodge is way up now. Thanks Hoot for the message about this coming out in Oct from Star/Chrysler for the much needed computor update. He was right on. Must have an awesome connection in the chrysler world. I told my service managers about this TSB coming soon, they thought I was crazy but had them check weekly anyway until walla. http://www.dieseltruckresource.com/dev/images/smilies/smile.gif