ok i like ford, work for dodge, and drive a chevy. all american me!

couple of questions
comparing the numbers from dyno tests the duramax lmm is putting out more torque and horsepower than the cummins 6.7?
fundamentals say that you get better torque out of an inline, which is contradictory to the numbers that i am seeing.
that puts the question of torque rise into my mind, i.e. an engines ability to keep producing horsepower under a load. i worked at a farm equipment dealership and ran the dyno often enough, why is it that todays diesels are able to defy the fundamentals of yesterdays engines.
thirdly does this senario prove that the lmm and powerstrokes are just as capable as a cummins or any other inline engine?

There was an article in one of the mags a while back where they tested the LMM, 6.7 and 6.4. They said the main difference was that the Cummins' TQ came on at lower RPM than the 6.6, so the Dodge was better towing off the line, but the GM was better towing at speed. I'm no expert, but I'd say the 6.6 takes advantage of its closer to square dimensions and its lighter rotating assembly to produce more peak power. I'd think an I6 with a shorter stroke would perform similarly. I have a Mercedes 3 liter I6 turbodiesel that pulls hard all the way to the governor at 5 grand. As you know most med/hvy duty truck engines are now and have always been I6s. There were more V8s in the 60s, 70s and 80s, but now most all have gone back to 6s. The best V8, the Mack E9, died out when thy were acquired by Volvo.

Nick

There was an article in one of the mags a while back where they tested the LMM, 6.7 and 6.4. They said the main difference was that the Cummins' TQ came on at lower RPM than the 6.6, so the Dodge was better towing off the line, but the GM was better towing at speed. I'm no expert, but I'd say the 6.6 takes advantage of its closer to square dimensions and its lighter rotating assembly to produce more peak power. I'd think an I6 with a shorter stroke would perform similarly. I have a Mercedes 3 liter I6 turbodiesel that pulls hard all the way to the governor at 5 grand. As you know most med/hvy duty truck engines are now and have always been I6s. There were more V8s in the 60s, 70s and 80s, but now most all have gone back to 6s. The best V8, the Mack E9, died out when thy were acquired by Volvo.

Nick


that is the basic jist of any v8 vs I6 argument.....

well, I am no expert either, but I will tell you I had a 07 Dodge CTD 5.9L towing my 9000# travel trailer I would get a whopping 8 or 9 MPG with it @65-70MPH. I Recently purchased an 07 Chevy LBZ and I am getting 14-15 doing the same job. YOU TELL ME, what the duramax is capable of compared to a crapppins, I mean cummins..... I was pissed to say the least with the performance out of my DODGE, not to mention the problem you will have with a dodge when you turn on the heat, traveling 70mph, towing a 9000# trailer in the dark of night, with your lights on,,,,,,, let me tell you what happens, every 45 seconds for 3-7 seconds you end up with a volt/power drop dimming your headlights to firflies. Dangerous as hell, Dodge's answer, "it is normal for our trucks, they all do it" they are correct, go to any dodge 06 or newer, flip the defroster on turn the heat all the way up, turn on the headlights and wait 1 minute, you will be able to watch the volt gauge drop like a champ for 3-7 sec and repeat every 45 seconds. DODGE SUCKS, traded my 07 with 25K miles on it for an 07 Chevy, and will never go back to dodge!

That may be the jist when speaking of American engines, but not of engines in general. For years Mercedes and BMW made I6's that revved higher than any of the V8s they made at the time; BMW probably still does It all comes down to physics; bore/stroke and weight of the rotating assembly.

Nick

I'm not in any way cheering the CUMMINS on, I personally think the DMAX/ALLY combo is the best out there. But you also have to keep in mind that DODGE has CUMMINS specifically detorque the engines for them. Look at the humongous torque gains that many CUMMINS owners get with only minor changes. A 12V 5.9L in stock form makes low 400's for torque, a fuel plate will put you up around 600 in the torque. Yet it will not add that much HP. This was DODGE's answer for drivetrain reliability. GM uses torque management instead.

I remember reading somewhere when the LBZ first came out the testers said they could feel the computer reining in the engine power at times. In '05 the standard issue 5.9 had 265 HP and 660 TQ, whereas the Dodge 5.9 was 325/610. I always assumed this was for driveability in the Dodge, but it makes sense that they were de-torqued for tranny reliability. As far as I'm concerned HP is just a #; torque is what breaks stuff.

Nick

everyone has their opinions, i dont know if the fact that everyone elses v8's disappearing is an oman or anything but i do know for a fact that i a sold on the cummins and the early duramaxs and also the 7.3 powerstroke. Ford has had over 2billion dollars in warranty work on the 6.0 ps. personally i love the 6.0, its strong and it will scream! again i think that the fact that dodge owners have found ways to hype up the cummins with relatively few mods is a testament to what works. i dont mean to offend anyone, and i dont think that a v8 diesel is stupid or a joke. but to back up my affinity for the cummins not just the 5.9 or 6.7 but any, i think that the fact that dodge has to detorque them and the fact that i can find the same 5.9 in a ram as in a case international tractor is amazing. obviously as you stated the fuel rate is reduced in the dodge trucks.

to the guy that said he had a dodge and didnt get squat for mileage, you have to break an engine in, its not just an a** hauler from the dealership
depending on how hard you work it it could take up to 30000 miles to break it in. youre mileage unloaded should jump from around 14.8-15 mpg to any where from 18-21 mpg. no crap. i work for a dodge dealer, if i could get a cummins in any other truck it would be awesome. the problem with the diesel craze right now and alot of criticizm is the fact that alot of the people that buy diesels dont use them they want to have the biggest truck and show off. big problems occur with modern diesels when you dont work them. dpf's plug up, turbos get smoked, and thus bad reputations are born. i am not an expert but i do study and try to gather all the information from every side of the court. that is part of the reason that i love this website.

as far as horsepower, i dont give a crap, you can hodrod your diesel all you want but when i load a truck down i want enough torque to pull whatever the hell i throw at it.

then the thing with the headlights i know of this problem and i have to say that i dont really prefer dodge over any other truck, the only reason i like to hit on the high points is the fact that noone else has a cummins yet.

I think that one reason Ford and GM have stayed with v8's is that most North Americans equate v8's with big power and I6's with low power and economy. It's because of our automotive heritage. Also, v8's fit better in platforms that are also offered with gas v8's and v10's.

Nick

I'm not in any way cheering the CUMMINS on, I personally think the DMAX/ALLY combo is the best out there. But you also have to keep in mind that DODGE has CUMMINS specifically detorque the engines for them. Look at the humongous torque gains that many CUMMINS owners get with only minor changes. A 12V 5.9L in stock form makes low 400's for torque, a fuel plate will put you up around 600 in the torque. Yet it will not add that much HP. This was DODGE's answer for drivetrain reliability. GM uses torque management instead.



Kind of going along with what he said.

Ever notice manufacturers have the same engine at different ratings. For instance my truck in 97 was rated at 215/440, but a 12v that went into a 650 and bigger trucks was rated at like 215/660 or higher IIRC.

Its all in what the customer wants, and i dont think dodge wants to try and put a tranny behind something rated in excess of 800 ftlbs.:rolleyes:

I had a 07 Dodge CTD 5.9L towing my 9000# travel trailer I would get a whopping 8 or 9 MPG with it @65-70MPH. go to any dodge 06 or newer, flip the defroster on turn the heat all the way up, turn on the headlights and wait 1 minute, you will be able to watch the volt gauge drop like a champ for 3-7 sec and repeat every 45 seconds.
Hmm. I tow 15k on a regular basis and i get anywhere from 11-14mpg depending on speed and wind. Also my lights don't flicker like that... Something must be wrong with mine.:D

really the only time that your lights should or could flicker is when your heating coils come on RIGHT after start up and your volt gauge WILL go nuts. in theory if it is extremely cold your engine might kick the coils on to heat the intake air mass. the coils draw a ****load of amps. other than that there has to be a problem with the truck, got my answer today at work.

My Dodge must be broke also. It doesn't dim the lights or move the volt gauge with the defrost on high.

For what it's worth, my Dodge is slower getting things going but pulls much harder than my Chevy past 40 mph. My Chevy acts like it's going to really take off but kinda fades once it gets in the higher gears. I even put a Juice/Attitude on it to help with mileage and make passing a little safer.

Kind of going along with what he said.

Ever notice manufacturers have the same engine at different ratings. For instance my truck in 97 was rated at 215/440, but a 12v that went into a 650 and bigger trucks was rated at like 215/660 or higher IIRC.

Its all in what the customer wants, and i dont think dodge wants to try and put a tranny behind something rated in excess of 800 ftlbs.:rolleyes:

They all play the same game. Computers make that so much easier nowdays. One manufacter comes out with x00 hp, the other has x00+10 hp, then the next is x00+15 hp, up and up and up, but nothing changes under the hood.

Remember when the extended cab trucks got the '3rd door' back in the late 90s? The big 3 all came out with it within the same year, go figure.

They know what they are doing.

Maybe in the big truck world, the I6 vs V8 is a big difference, in-frame rebuilds, lighter, etc, but in a pickup it's obvious that it doesn't matter. They're just two different types of engines.

Maybe in the big truck world, the I6 vs V8 is a big difference, in-frame rebuilds, lighter, etc, but in a pickup it's obvious that it doesn't matter. They're just two different types of engines.

I agree, the v8 turbodiesel also has a better power curve for a light duty truck. V8's run smoother too and I don't like that cummins shake.

the i6 also has a flatter torque curve so do the v8's make a better car or hot rod diesel. i'm still sold on the i6 everything on the farm has one except for the grain truck, naturally aspirated v8 cat. the only i6 that we have that i dont like is our massey, it has a perkins p.o.s. it doesnt spool up fast enough when you shift and the turbo lag sucks ***. its front wheel assist and has got to be the slowest turd i have ever seen. had a leak in the radiator into the intercooler. blew steam all over. got a huge loader on it. not to impressed with the accessory drive either. anyway i dont like it the tractor is a beast but i like my 8010 allis better. spools up so fast. power shift... a little smoke... then youre screamin. thats a cummins for you. the most bang for the buck. had the injector pump rebuilt after the low sulfur diesel. the pump got cranked up a little so it burns fuel faster but dude if you hit a hard pan stomp on the diff lock and your blazin through any thing. i did bury it up to the draw bar in a swag this spring discing a neighbors field, no luck getting it out , had to get the massey pissed me off. i love that allis. then the next week i got it stuck in a spring on the back side on a terrace at granddads place. had to pull it out again, snapped the chain three times but i kept going.