Still another MPG question.

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Hi all, I'm a new member and a new owner. I know the MPG question has been beaten to death in previous posts, but this being my first Cummins w/ an auto trans, I'll ask anyway. This is my 3rd diesel truck, The first was a '93 DC 4x4 CC 5sp 3. 54. With a 500lb. contractors cap and tools it got about 18-18. 5 mpg once it broke in at approx. 20,000 miles. The next truck was a '94 PSD X-cab 5sp 4x4 4. 10 that got about 16-16. 5 once I got rid of the auto hubs w/ the same cap and tools. My new '01 DC QC 4x4 auto trans 4. 10 w/ 2000 miles got 14. 5-15 MPG on the first 3 tanks w/o the cap and the last fill-up was 12. 9 w/ the cap. My last Cummins only picked up 1 mpg once it broke in, so I'm disappointed w/ my current milage. One of the main points of going back to DC was for milage gains. Two freinds w/ '99 DCs are in the 18-20 mpg range. Both with AT, one w/ 3. 54 & one w/ 4. 10. and no caps. Yes, I know, it needs more fill-ups to get a true comparison, but does this sound normal? I will say that the truck drives great and seems to have enough power for me at this point. It has a nice turbo whine, so I don't think I be removing the silencer ring AND (are ready for this?) the first oil change was a piece of cake. Oh, one more thing, when I change the oil, I removed the rubber hose to the air filter. When I spun the turbine, it had a spot where it dragged. As I recall, the '93 spun smoothly from the first oil change. Is this a break-in thing or something I should have checked out? Like previous postees, sorry for the long wind post, but that's what this great site and all of it's great member are for.
Thanks in advance, Tom

 

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The turbo should spin VERY FREELY. Have it checked out , you are losing some boost if it is not spinning very freely.

 

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Tom,get that thing back to the dealer ASAP,your turbo should spin smooth,don't let them try to tell you it's fine. I assume that your engine was warm when you changed the oil,check to see if the drag is there hot or cold,you want to be able to duplicate the drag for the tech,otherwise they might just blow you off. Whether the turbo problem is effecting your mileage I can't say,but bring up the poor mileage problem when you take it in. It may need valves and timing adjusted. Good luck and welcome to the TDR!

 

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I know the MPG question has been beaten to death in previous posts...

Aw heck Tom, mpg hasn't been beaten NEARLY as often as "more power", we enjoy it all!
One reason I flog this board is because somebody here at home is tired of listening to me talk about my beloved truck. Relative to mpg, I concur - unless you were 100% stop and go with lots of idling, or you average 85 to 90 mph on the freeway, then your numbers seem low. Could be either your engine, or your transmission. Knowing that Cummins built the engine, I'd be tempted to suspect the transmission first, but the good news is, you're under warranty, so you can get if fixed for free whatever it is, as long as you persist. I agree - have 'em check the turbo pronto. And DOCUMENT - if they blow you off now and you have turbo failure 10 miles past your warranty expiration, you still win!

 

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tmacc, you figures are very low. i have only 8100 miles on mine at this time, and mine isnt anywhere near getting broken in. i went on an extended trip, to visit family, and drove 260 miles each way. going there i drove 65 mph w/air cond on, and got 24. 8 mpg. on the was back, it was cool outside so no air cond was needed. i drove 65 mph and got 26. 9 mpg. if your turbo blade is dragging on something, take it immediately to the shop. if the thing get out of balance and blows, you will be waiting a long longer to get it repaired, much more damage. good luck, and let us know how it goes.

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Y2K, 2500, 4x2, QC, patriot blue. K&N, silencer ring put back in.

 

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Hey guys, thanks for your replys. illflen, I went out after reading your post and checked the turbo again. If I spin the turbo counter clockwise, It sometimes "drags", but it seems to spin smoothly clockwise, which appears to be normal operating rotation. The truck was cold when I checked this time. I'll check it tomorrow after its warmed up to see if it still drags. As far as setting the valves and timeing, I didn't know there was anything that could be adjusted. I've read of reflashing on this site in other posts, but as far as anything else I have to plead ignorance. I didn't keep the '93 long enough to learn all the idiosyncrasies of Cummins motors (good motor, really bad truck) and the PSD, well I did put 190k on it and I CAN tell you it's idiosycrasies, but we won't go there, that's for another site. Well OK If you insist, water pumps evry 40k, glow plugs every 80k, injector o-rings every 80k, belt tensioner pully every 60k and my favorite, at 40k of the 8 nuts and bolts that hold the "twin beam" front axle on, 2 bolts were broken, 2 nuts were missing and 3 other nuts were backed off 1/4-1/2" and the final nut was finger tight, I guess 10 cents worth of loctite cost too much. OK got that off my chest. HC, I'll keep an eye(ear?) on the trans. You said it when you said "beloved truck". There is something about them isn't there. Thanks again guys.

 

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Tmacc... As the other posts have stated Your mpg is low. . I drive mine hard and started out at 16mpg and it has climbed to 18mpg (20,000). I heard of other claims much higher--most of the 2WD. .
If and When Warranty are no longer concerns it does seem that all of the mild BOMBing methods increase mileage. (According to posts)
I would check all of the intercooler clamps first.
Please post if you do find something wrong.
LOL kwik

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"Have you driven OVER a phord lately"
2001 2500 BRT WHT SPORT QUADCAB 4X4 ETH 3. 54LSD TRLR CMPR PKG ALL OPT XCPT LTHR

[This message has been edited by KWIKKURT (edited 09-25-2000). ]

 

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tmacc,

Check my posting to see what I drive - sounds similar though. I only have about 3500 miles and have seen a low of 12. 9 mpg (most recent!) and a high of 18 mpg (totally highway miles). I'm not completely stock anymore so we'll see what happens to the mileage. I am also hoping to see a little jump when I finally break it in.

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'01 2500 SLT+, QC, LWB, 4X4, 3. 54s, AT, SPA guages, Alpha Liner, every option but running lights!

'98 DUCATI ST2 "Bombed" 944CC with Ducati Performance Carbon Fiber Exhaust, F. I. M. Chip, K&N and "modified" air box.

 

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tmacc, I just got back from BC about 2400 miles each way. I got 21. 5 at 75 mph, 19. 5 at 85. If I could hold 65 mph it would be much higher. This was lightly loaded, about 700lbs. Locally I get 17. 5.

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Tom W in Austin Tx 98 24v 2500 Quadcab auto 3. 54 lsd Rhino white/driftwood Banks Stinger Plus Manix grill nerf bars ,coming soon Bill K's fixes

 

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I just put about 1500 miles on my truck in the past few days. Here's what I found.

Stock eth/dee 3500 4x4 4. 10 with 2500 miles total at the start.

First tank of the trip with some country road driving and freeway at 65mph: 19. 5 mpg.

Second tank 100% freeway with 65mph cruise control: 20. 3 mpg.

Third tank 100% freeway at speeds of 70 - 80 mph: 17. 8 mpg.

26 gallons to fill up when the low fuel light comes on.

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'01 ETH/DEE 4x4 QC SLT 3500 4. 10

 

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Well guys, thanks for all the posts. illflem, I checked the turbo with a warm engine and it spun very freely. Maybe it was cold oil in the bearing when I noticed it before. It does take a while to drain the crankcase when you've just back the drain plug a little till it drains out enough to remove it. Tom W. & Mike, I get a stomach ache when I hear about your kind of milage. Don't get me wrong, I happy for you, but what's wrong with my truck? I very rarely put my foot in it. And Scooby, My condolences on your milage, But you sure have a sweet toy to take your mind off it. Oh well, it's still a great truck and I'm sure I get to the bottom of a some point. I did check all of the intercooler connections right after I got it home. They all appeared to be tight. I snugged them up a little. Anyone have any other suggestions?

 

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tmacc, I had good millage up front but then it went down for about 1,000 miles don't know why but then I towed my 5th wheel which weighs in at 12,700 and that realy helped with the economy and the power, you say you do not put your foot in it, that might just be part of the problem.

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TAZ... 2001 2500 SLT+ 4X4 Auto ETC Cummins, LSD 3. 54,Quad Cab, Long Bed, Agate Leather, White/Driftwood Exterior, Sliding rear window, Camper Special Group, Towing Group, Cab clearance lights, Diesel Dynamics Stage-3's, DD Boost Module,SPA-Technique Digital Dual Gauges (Pyro/Boost, Trans pressure/temp) Aux. Backup lamps. BNM 5th Wheel Hitch, Additional Body Molding on Bed. BD Torc Loc, BD Pressure Loc, Line-X bed-liner. DTT's TC & VB. Pac Brake

2000 32' Aljo Triple Slide 5th Wheel.

http://www.ramtaz.com

Add on's to come: Power Edge Box,and any other Ram Runner required modifications...

 

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Might be about right for a unbroke in 4. 10 !
light loaded 4. 10 gets about 10-12% less mpg than a 3. 54.

 

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Hi Folks,
I'm also new to the Register and since this is my first diesel, have been going through back posts to see what I can learn. I'm also curious about the mileage issue.
Have an 01 5. 9 Turbo, 4 x 4 with 4. 10 gearing. Right now it has only 1900 miles on it and I have left the trailer and my offroad Jeep attached as much as possible, even for city driving, so motor can be broken in with the load it will be carrying.
So far am averaging around 14. 5 mpg. That's a combo of highway/city... and virtually all with trailer/Jeep attached. I'll keep an eye on actual figures so they can be added to input. Grin, I can see I have an awful lot of reading to do in the Register.

Ray

 

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Just got my first diesel 9/21/00. Took a short 400 mile round trip pulling 13k 5er and on the return trip in some hills and a headwind just averaged 9. 5MPG. I've got alittle over 1000 miles and maybe I'm just anxious for good mileage but so far I'm not to impressed!

 

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Originally posted by Crackerjake:
Just got my first diesel 9/21/00. Took a short 400 mile round trip pulling 13k 5er and on the return trip in some hills and a headwind just averaged 9. 5MPG. I've got alittle over 1000 miles and maybe I'm just anxious for good mileage but so far I'm not to impressed!

if you want some input about what to expect from your rig, you need to let us know what you have, the gearing, how many miles on it, any add-ons(engine), flashes, and your driving habits. we would be glad to give you our input. #ad


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Y2K, 2500, 4x2, QC, 3. 54 ls, patriot blue. K&N, silencer ring put back in. 8100 miles as of 9-25-00

 

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Sorry 'bout that. Guess I was a little short of info. Not only am I new to diesels but also to talking on the computer. I've got an 01, 3500, dually, 410, no addons, and pretty easy on the pedal.

 

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sdalton--Oh. I forgot to tell you that it is a 4x4, automatic. I drove with overdrive on on these hills on my trip to Hannibal. When I took it out of overdrive, the RPMs went to about 2700 to 2800 and the manual says not to go past 3200. I maintained about60-65 mph. I lost about 15 mph on a couple of long hills and 5-10 on a few others. The auto shifting was smooth- never jerky. I've just got about 1010 miles on this truck.

 

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I have read on other post that on the "over valved" engines the mileage gets better as miles are put on truck. You guys with 4. 10s don't expect same mielage as 3. 54s.
tmacc your 24 vavle is much different from your 93 12 valve.



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Missouri Mule 96 White 4X4 ST club cab,(grey int. ),5 spd, 3. 54 reg dif, 8 ft bed, 1 ft high cheater boards, front and side of bed,Pofile V bug shield,
99 Freight liner FL60 blue Cummins 24v 215 hp, 520 torgue,6 spd 3. 59 no spin rear, 16 ft dry box (white) 19. 5 low profile tires,Weight 11,000, gvw 23000, 11 to 12 mpg
Bill Thomas (Wild Bill)

 

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Welcome aboard Crakerjake

Originally posted by Crackerjake:
on the return trip in some hills and a headwind just averaged 9. 5MPG.

what is fuel mileage mt in town and hiway ?:
Was the 9. 5 just on the retrun leg in hills and headwind or the whole trip ? : was this calculated or from trip computer ? : did you take the same rout both directions ?: What does your rig weigh ?:
were you able to pass other rigs ?( gas or diesel)
Out here in the mountains 10 mpg stock and the speeds you mention are ave for me but I also have 5 - 7% long grades and 20-40 mph winds to contend with. Rig grosses approx 17,500#
With enhncements can hold speed limit (75) on all but longest grades and still get 10 mpg.
It should get a little ( I said little ) better when you hit 5k, 8k, and 10k miles


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2K, 2500,Laramie,Quad,4x4,3:54LSD"slushbox 250 RPM drop WOT shifts", , reese 15k 5th slider, LAVERNGE BULL BAR,WESTIN NERFS, TA's, DD1's, VA, boost & elbow onboard, 4" & 9000's in transit w/more to come
pullee #1 26' Arctic Fox 5th
#2 22' car hauler w/ 76 Pinto 392cid or 68 Cyclone GT Cobra Jet FB
NRA,VFW,SASS