Dodge diesel 5.9l or the 6.7l

[arcticdodge]

Still looking at buying a truck, now thinking of going newer than the 06-07 with the 5.9. Maybe go with the 08-09 6.7l. I like that you can do lots to the 5.9 and that they are a tried and true motor. Is there much that you can do with the 6.7. I am looking for great gas milege , reliability. Not sure about the 6.7 with the blue-tec. Any thoughts on the two motors. Never had a diesel before so I want something that has power. Thanks Mark:d

 

[pipes]

Still looking at buying a truck, now thinking of going newer than the 06-07 with the 5.9. Maybe go with the 08-09 6.7l. I like that you can do lots to the 5.9 and that they are a tried and true motor. Is there much that you can do with the 6.7. I am looking for great gas milege , reliability. Not sure about the 6.7 with the blue-tec. Any thoughts on the two motors. Never had a diesel before so I want something that has power. Thanks Mark:d

I own a 05 5.9. good fuel economy. If I drive @ 100km I can get up to 25 mpg running with truck alone. Pulling a 30.5' Jayco Eagle lite I averaged just under 15mpg in the mountains of BC. Bully Dog tuner AirRaid air box, a claimed 440 Hp running in extreme. Never had idt on the dyno so don't know for sure but it does have a lot of grunt.

I'm not sold on the 6.7 yet. haven't heard too many good things about them with all their pollution control crap. Time will tell.

Can't go wrong with the tried and true 5.9

just my opinion, if that counts

 

[Captjacksparrow]

I've got an 07 1/2 Mega dually with the 6.7 and the 6sp auto. The motor is awesome, pulls very good and they have chips and programmers for them as well. I only have 53000k on mine but no issues. The milage is not quit as good empty as the 5.9, I have a hard time getting 20mpg but I have a 17 thousand pound 5th wheel toy hauler and if I'm not bucking a head wind I get over 10 with it and 11+ with a tail wind. It's actually better than my 03 5.9 was with the same trailer. The thing I really like is the tranny. If your going with the auto you need to go with the 6.7 because you can't get the 6sp with the 5.9. The 6sp is a WAY better tranny than that 4sp. I can't count how many guys I know that had major trouble with the 4sp, and some with hardly any kliks on either. Just my opinion, I've had both trucks but my 03 was a 6 sp std and that's a good tranny. Just be prepared to put a bigger clutch in if you do much to the motor.

 

[arcticdodge]

Wanting an automatic, and every dodge I have owned Except two had to have tranny's done to them. From the cars/trucks I had to the wife's mini-van. I am more interested in really good fuel milage over the really big power. I have a friend with the 5.9 who gets about 20mpg with his on a 4" lift and 35" tires running a programmer. No trailer to pull except the toy trailer couple times each season. Will the 6.7 get any better mileage as it wears in more? :d

 

[pipes]

I have to agree with the catain. The 6 speed tranny is a better tranny, the other nice feature with the 6.7 is the exhaust brake. I believe it is a standard feature on the 6.7 with the auto. not sure about the manual.
Just yesterday I ordered the Banks exhaust brake and smartlock for my 5.9 so that I have better braking in the mountains. I will let you know what I think of it once I install it.

Captain any comments of the question of improved milage once you get some miles on yours. Sounds like your happy with 6.7 and you have a 5.9 to pit it against so I trust that you will keep us up to date on the pros and cons.

Lets keep this thread alive so that we can each learn from one anothers experiences.

 

[08154XP]

I work at a dodge dealer and we have very little motor or tranny issues with the new 6.7. Just that pollution control crap causes some problems because they are not meant to idle. Tranny and exhaust brake on the 6.7 are awesome and work very well. Fuel mileage does get a little better with break in but not a whole lot. Best thing to improve mileage the a dpf (diesel particulate filter) delete exhaust that some aftermarket companies sell. Now this does void warranty with the exhaust system and perhaps turbo, depends on what causes the issue but some of our customer state the can get 24+ MPG with that system. Personally I have a 5.9L but the 6.7 does have some very nice feature from factory. Any questions feel free to ask or PM me.

 

[FossY]

you coulde told them that every 6.7 comes stock with exhaust brake

im a dodge tech myself and have to say

the dpf does work good when the owner finally understands it !!!!!

trani issues yes but there known

also the 6.7 have issues but not really inside the trani its the dualmass flywheel which screws up every once in a while but aint a biggie to change

best thing for power and mileage so far i would say

go
-edge chip (6 setting)
-good open air intake
-17" rims its pretty impressive that we have 2 guys in the shop same trucks just one has the 20s on and gets 4mpg less than the one with the 17s

 

[DEVER]

I've got an 07 1/2 Mega dually with the 6.7 and the 6sp auto. The motor is awesome, pulls very good and they have chips and programmers for them as well. I only have 53000k on mine but no issues. The milage is not quit as good empty as the 5.9, I have a hard time getting 20mpg but I have a 17 thousand pound 5th wheel toy hauler and if I'm not bucking a head wind I get over 10 with it and 11+ with a tail wind. It's actually better than my 03 5.9 was with the same trailer. The thing I really like is the tranny. If your going with the auto you need to go with the 6.7 because you can't get the 6sp with the 5.9. The 6sp is a WAY better tranny than that 4sp. I can't count how many guys I know that had major trouble with the 4sp, and some with hardly any kliks on either. Just my opinion, I've had both trucks but my 03 was a 6 sp std and that's a good tranny. Just be prepared to put a bigger clutch in if you do much to the motor.

Great post, I have to agree also. the 6.7 is a strong motor and with the 6sp w/ tiptronic its a great combo. 6.7 does not get as good mileage. One of the main factors is your rear end. a 4:10 wont get as good mileage regardless what motor its married to. 3:73 to a good run around setup, but not for the heavy loads IMO

 

[Cyle]

You couldn't pay me enough to own a 6.7. My dad has one, and I have a 04 5.9 so I drive both quite a bit, and I absolutely hate it. The auto trans is terrible for towing, it downshifts SO hard, and never knows what gear to be in, it lugs the engine so badly. The exhaust brake is the only good thing I can say about it. MPG is a joke compared to mine, and I have 6" lift and 37" MT tires. If your getting an auto for sure, I can't say which one is better, but all of them are terrible for towing. Just because it has an extra 2 gears doesn't mean anything, it still gets worse MPG with lower RPM's. The emissions is a joke, if you leave it stock plan to have the check engine light on pretty much ALL the time. Because they throw so many codes. My dads has let him down 1 day, when it started but white smoked like crazy and wouldn't rev up, left it sit for a day and it was fine, and almost another when it just died on the highway for no reason. It has 80,000km on it and has been nothing but a problem. When it was new towing 11k lbs in the city, he couldn't even get 400km to a tank.

MPG is pretty debateable, many people use the lie-o-meter, others use canadian MPG, etc. So many varibles, even two identical trucks can see a bit different mileage. But one things for sure, the 6.7 gets less MPG then the same 5.9.

They have so many emissions problems it's not even funny, unless you delete the DPF which voids all your engine warranty, you will have issues. They have quite a bit of aftermarket parts for them now though.

 

[pipes]

You couldn't pay me enough to own a 6.7. My dad has one, and I have a 04 5.9 so I drive both quite a bit, and I absolutely hate it. The auto trans is terrible for towing, it downshifts SO hard, and never knows what gear to be in, it lugs the engine so badly. The exhaust brake is the only good thing I can say about it. MPG is a joke compared to mine, and I have 6" lift and 37" MT tires. If your getting an auto for sure, I can't say which one is better, but all of them are terrible for towing. Just because it has an extra 2 gears doesn't mean anything, it still gets worse MPG with lower RPM's. The emissions is a joke, if you leave it stock plan to have the check engine light on pretty much ALL the time. Because they throw so many codes. My dads has let him down 1 day, when it started but white smoked like crazy and wouldn't rev up, left it sit for a day and it was fine, and almost another when it just died on the highway for no reason. It has 80,000km on it and has been nothing but a problem. When it was new towing 11k lbs in the city, he couldn't even get 400km to a tank.

MPG is pretty debateable, many people use the lie-o-meter, others use canadian MPG, etc. So many varibles, even two identical trucks can see a bit different mileage. But one things for sure, the 6.7 gets less MPG then the same 5.9.

They have so many emissions problems it's not even funny, unless you delete the DPF which voids all your engine warranty, you will have issues. They have quite a bit of aftermarket parts for them now though.

My MPG calculations are not the indication on the overhead display. I do mine the old fashion way. Calculated with odometer reading and pump reading.

 

[Cyle]

My MPG calculations are not the indication on the overhead display. I do mine the old fashion way. Calculated with odometer reading and pump reading.

Yea, but that isn't perfect either. Unless you fill it up the EXACTLY the same point. If you put in say 1 or 2 gallons less, you will think it is better mileage then stated. You also have to consider factors of where you drove for that tank, and range it over tons of tanks IMO. It's tough to get a real good estimate.

 

[pipes]

Yea, but that isn't perfect either. Unless you fill it up the EXACTLY the same point. If you put in say 1 or 2 gallons less, you will think it is better mileage then stated. You also have to consider factors of where you drove for that tank, and range it over tons of tanks IMO. It's tough to get a real good estimate.

true that. but when I do my filling up for the purpose. of calculating I fill it till I can't get any more in. Pain in the but because of the fuel foaming. And yes you are right, should average over several fill ups to be more accurate.

 

[Captjacksparrow]

To address what Cycle said. One bad 6.7 doesn't mean they are all bad. Take my 03 5.9, here's a list of what went wrong in the first 45000km's, dropped two valve seats 8 thousand k apart, 2 lift pumps, 2 injectors, two.................we'll call them computer glitches, 2 u-joints, cd player had to be fixed, a turbo and a few small things. I didn't give up on it and it was good after that. I did get good mileage, definatly better than my 6.7 but with a quad in the back through the bc mountains driving 120 kliks I've gotten over 700 k to a tank, close to 20mpg, with the 6.7. The tranny shifts pretty good, a bit hard at times and can lug lower than you want but I just shift it manually with the little rocker switch and it works awesome. The engine brake is great as well. I would not go back to a 5.9 now. I love my Mega Cab.

 

[Cyle]

To address what Cycle said. One bad 6.7 doesn't mean they are all bad. Take my 03 5.9, here's a list of what went wrong in the first 45000km's, dropped two valve seats 8 thousand k apart, 2 lift pumps, 2 injectors, two.................we'll call them computer glitches, 2 u-joints, cd player had to be fixed, a turbo and a few small things. I didn't give up on it and it was good after that. I did get good mileage, definatly better than my 6.7 but with a quad in the back through the bc mountains driving 120 kliks I've gotten over 700 k to a tank, close to 20mpg, with the 6.7. The tranny shifts pretty good, a bit hard at times and can lug lower than you want but I just shift it manually with the little rocker switch and it works awesome. The engine brake is great as well. I would not go back to a 5.9 now. I love my Mega Cab.

I'd like to know how you calculate MPG. Because 700km on a "tank" is far from 20 MPG. That would mean you only put in 80L, which is no where near a tank. 20 MPG would mean over 1100km to a tank.

Sure there are some happy 6.7 owners out there, but many many more disappointed ones. They ALL get terrible mileage, and all are plauged by emissions. If your going to get a new truck before it leaves warranty it might be ok if you don't mind trips to the dealer, but for anyone keeping for a long time, it is a time bomb. When that emissions stuff goes (and it WILL) the trucks won't be worth fixing.

I am not addressing my facts based on one truck. Go to ANY Dodge Diesel forum, there are SO many people with problems. Almost no one can say it is problem free, even if they just have the CEL it is a pain to deal with and shouldn't happen. The design is terrible, the turbo nor the engine will last as long as a 5.9, there is a reason so many are having turbo problems. And the turbo on ALL of them will be going out long before one in a 5.9 will because of the stupid setup.

The ONLY advantage is a exhaust brake, the auto is nothing special. MUCH better off with a 5.9 and adding the exhaust brake if you want it. I have towed and driven a 6.7 a ton, and absolutely hate it. Empty I can live with it, extra bit of power, but throw a heavy load behind it in the city, and you will want to kick the dash in because of how bad the tranny is. I will take the 48RE over the 68RFE ANYDAY. It NEVER knows what gear to be in, and makes towing a chore. I am much happier rowing threw the gears myself.

I will never "downgrade" to a 6.7. My 5.9 makes more power then a stock 6.7 that costed a whole $400, more reliable, better MPG, and better towing, and it's a lot cheaper!

 

[CUSO]

Wanting an automatic, and every dodge I have owned Except two had to have tranny's done to them. From the cars/trucks I had to the wife's mini-van. I am more interested in really good fuel milage over the really big power. I have a friend with the 5.9 who gets about 20mpg with his on a 4" lift and 35" tires running a programmer. No trailer to pull except the toy trailer couple times each season. Will the 6.7 get any better mileage as it wears in more? :d

For the few times that you pull a toy hauler to the hills.... do yourself a favor and stick with a gasser.... unless you plan to hold on to your truck for 300,000 km, which prolly 95% of the owners never do, or tow all the time. After the cost premium of the motor, the costs of maintenance, lousy winters and cold starts, noise, smell, etc..
Plus you never should buy a diesel for the fuel mileage. buck for buck, you break even at 250,000 miles.

just My .02$

 

[Captjacksparrow]

1100 kliks to a tank......(I usually don't run my tank right empty, it usually takes 115 to 120lts when I fill) so 1100 kliks to 120 lts is 25 to 26 mpg. Not sure how your figuring out mileage but you need to get a fuel economy calculator like I have it works great and bang on every time. The computer is rarely right so I don't use it. You are right I wasn't 20 mpg bang on but I was close, I went and dug out my book where I keep track of my mileage and I had gotten 724 kls, to 107 lts. That's 19 or so. That was the best tank so far and it doesn't do it often but It's not too bad for a Mega dually. As far as the tranny goes I don't get how your having such a hard time shifting it. I pull an 18000lb 13 1/2" high 5th wheel all the time and the tranny works awesome. The 4 sp is not enough gears for heavy loads. That's why the bigger the truck the more gears you need. The 4 speed is the worst tranny out there for reliability. There is very few that made it to 100,000 kl if they were doing any pulling at all or had any power. If you had the one that's been reliable then that's good but I wouldn't keep it long. I had a 6 spd std in my 03 and it was a great tranny.

 

[Cyle]

1100 kliks to a tank......(I usually don't run my tank right empty, it usually takes 115 to 120lts when I fill) so 1100 kliks to 120 lts is 25 to 26 mpg. Not sure how your figuring out mileage but you need to get a fuel economy calculator like I have it works great and bang on every time. The computer is rarely right so I don't use it. You are right I wasn't 20 mpg bang on but I was close, I went and dug out my book where I keep track of my mileage and I had gotten 724 kls, to 107 lts. That's 19 or so. That was the best tank so far and it doesn't do it often but It's not too bad for a Mega dually. As far as the tranny goes I don't get how your having such a hard time shifting it. I pull an 18000lb 13 1/2" high 5th wheel all the time and the tranny works awesome. The 4 sp is not enough gears for heavy loads. That's why the bigger the truck the more gears you need. The 4 speed is the worst tranny out there for reliability. There is very few that made it to 100,000 kl if they were doing any pulling at all or had any power. If you had the one that's been reliable then that's good but I wouldn't keep it long. I had a 6 spd std in my 03 and it was a great tranny.

Fuel economy calculator? LOL I can calculate it in my head, it's pretty basic. You are using Canadian gallons which is the difference. Canadian 20 MPG is nothing to be boasting about on the highway. I can easily get 26 canadian MPG on the highway with no problem, it only drops to around 20 with a decent load. The 4 speed was a fine tranny, just yesterday one guy I met had 240km on his 06, chipped since 50km still on the stock tranny. My bros has 140km on the stock tranny. The 47RE wasn't very good, but the 48RE is pretty good. 4 speed is PLENTY, these trucks don't pull squat for weight, in comparison. The biggest problem is people don't know how the properly maintain and drive them. Many last easily 300,000km. And saying 4 speed is pretty general, how many 4 speeds has Dodge put in the 2500/3500 over the years? 4? 5? I don't have a problem shifting it, I just put it in tow/haul and let it do it's thing, but it downshifts so hard it's stupid, and lugs the engine badly, which is NOT good for it.

 

[pipes]

OK boys enough with the pissing contest. Arcticdodge started this thread with the hopes of good sound advice. Your pissing contest may just convince him to buy a Ford or GM.

 

[Cyle]

OK boys enough with the pissing contest. Arcticdodge started this thread with the hopes of good sound advice. Your pissing contest may just convince him to buy a Ford or GM.

No pissing contest here, just want to make sure the right information is there. That would be scary if he would downgrade like that

 

[Captjacksparrow]

Just cause it's your opinion doesn't make it right, I love my 6.7 6 sp and you like your 5.9 4 sp, let's just leave it at that. I will say that I agree with you on the tow haul, that's why I quit using it. They do have some work to do on that. I just leave mine in normal mode rest my hand on the shifter on the hills and shift it with the little button. I totally forgot about tow/haul and that it shifted that way. I've always shifted automatics myself because they don't shift right on their own anyway, not even the mighty Allison. Dan