I just wanted to get everyones opinion please. All my buddies and other people I talk to about diesels, say Caterpillar your just payin for the paint. Then they say Cummins is great, wonderful, the best ect. But WHY?? Thank you.

 

Because they are a well built and reliable engine that can make stupid HP and torque for cheap.

 

Cummins doesnt compare to the Duramax with the Allison Tranny, The Duramax is the best right now but Ford has the new 6.7 Diesel coming out so we will see how that is. The cummins might just be the worse out of the 3 American trucks. Just my opinion.

 

Thank you for you replys, but is the 6.7 Cummins reliable, cheap hp tq, with maximum hp. and tq.? This is what I probably should have said. I apologize. Alot of the times its always about the 12 valve. I know about the 12 valve. How about the 6.7?

 

That is true, Diesels can make some crazy horse and torque for cheap. My dad just bought a $400 programmer for his Duramax and installed it on stage 1 settins. That only increased both his HP and TQ by 100 at the rear wheels. Just think if he actually put it on stage 7 which it is capable of, I guess you get about a 200 or more HP and TQ gain then. But then your tearin stuff up (would be fun at the track though). Not bad for $400 considering I just spent $5,000 just to get about 150 HP and TQ gain to the rear wheels.

 

If power is what you're after, stick to either the 12 valve or 24 valve 5.9. The 6.7 has too much emissions junk on it.

06, there is a tune for the new 6.4 Powerstroke which ADDS 310 HP. Just by pressing a button.

 

Thats sick, sometimes I wish I had a diesel. Maybe I'll get the new Ford 6.7 Diesel in a couple years after it has been on the market for awhile and any of the problems it might have are fixed and a good programmer is made for it. I just hope the new tranny in it can compare to the allison tranny.

 

Oh and with the programmer his gas milage went from 16MPG to 23 when not towing and from 9-10MPG to 16 when towing. Thing pays for itself and more.

 

OK Friend of mine (07FX4Chick) asked me to come over here and add some input.

Why she sent me this thread...let me tell you about my current rig & experience:
I drive an 06 Dodge 3500 5.9 CTD. Mod's include: S&B intake, Jacobs Brake Exhaust Brake, Air Dog 150, Smarty programmer, 5" turbo back exhaust, leveling kit rolling on 33" Pro Comps.
Past Rigs:
07.5 Dodge 6.7 CTD 2500
97 Ford 7.3 Power Stroke F250
too many gas powered rigs to count.

With the HUEI coming out of the Fords and the new Scorpion motor there is a HUGE possibility for a solid motor in the Ford body. I personally am a tad nervous about the engine bay

Going to be a hard time working on it without being able to remove the body.

The HEUI system greatly increased the cost of several modifications commonly performed on diesels. The system itself is a good design as long as it is remembered and you don't treat it like any other rig. Until that truck gets to full temp you do not have full oil pressure and that effects injection. The other big issues for the 6.0's & 7.3's are just a little work to get around.

The Duramax is a great highway motor. There is no doubt it is the quietest and has great fuel efficiency. With proper modification it can handle good weight w/o the EGT's going crazy.

Now why is the Cummins a top-notch motor and why at the track & on the dyno do they always put up good numbers? Great design, solid metal work, proven technology.

The CTD is an inline straight block. That design is proven time and time again for strength and durability. We can sit and argue the pro's and con's of a valley design vs a straight until we are all blue in the face. It's a never ending battle that all gear heads will have.

The ISB (the 5.9L entered Dodge family in 98.5, redesigned to a high pressure common rail in 04.5 and run tell early 07) motor is not only put in Dodge vehicles. Cummins uses that block for everything from generators to Over-the-Road trucks. This speaks volumes to the strength of the motor.
The CTD 6.7 aftermarket has come a long ways since 07. The 6.7 had reliability issues at first. The 07.5 & early 08's had turbo / EGT / DGF issues. By mid 08 they had a new turbo design out and MOST owners have not had many issues. You will see a lot of companies (mainly in Canada) producing DPF delete kits. **These are not fully legal in the US and will void your Emissions Warranty** Once installed owners are seeing a solid 2 mpg jump. Blocking the EGR also reduces the wear on the turbo (the 6.7 uses a VGT so the EGR puts sooty air though the turbo). Stock a 6.7 will run and pull as well as a stock 5.9 with no questions asked. There are several programmers out there now for the 6.7 that add fast easy hp / tq to the truck. Some of the aftermarket parts will run a tad higher than 5.9 parts though because of the changes to the turbo.

The old school 12v's ('91 - '98 Dodges) are an art to modify for big hp / tq numbers. The are all mechanical. There is no plug and play HP for those rigs. You have to get your hands dirty and really build the motor up. The "big" numbers for a built 12v are not as high as a 24v Cummins - just pure physics and the fact they are mechanical not electronic. But man oh man when you get a 12v built up and rumbling nice...does it ever sound sweet

The early 24v 5.9 (98.5 - 04) are good solid power plants. There are a few weak points that must be addressed if big numbers are the goal. The fuel & lift pumps like to go out; but those are both driveway swaps. There are an abundance of parts out there for them and you can take that power plant almost any direction (sled pull, hp / tq #'s, drag strip, hot shotting, daily driver).

The newer 24v's (04.5 - 07) are the easiest to modify. The after market for this motor is huge. There is just enough electronics on it to make plug and play power a real serious option. With a few hard parts and some electronics it is not uncommon for these rigs to roll over 600hp (no I'm not that high..I need to do my transmission before I push my electronics up to get those numbers). The transmission is a weak point. Not so much because the trans is bad...but because it was not designed for the TQ numbers the 5.9 puts out. Baking the TC & clutch packs are very easy to do.

So which one is better? That's easy ... The one in your driveway of course

No it really comes down to what in the world you want to do w/ your rig? Are you going to be hauling 18k lbs every weekend? Are you building a pavement princess? Are you looking for a drag truck? Do you just want the biggest bestest rig to ride to work in?


If the Allison is a huge selling point for you...just remember an Allison 1000 tucks behind a 5.9 w/ one conversion plate

 

My Dad has a 94 12 valve with over 1/2 a million miles on it now. The only thing he has done to it was adjusted the valves once that I know of. That motor has tore 3 trannys and 2 clutches too. He pulls 5-7k pounds every work day...

 

Cummins was designed and built for the medium truck segment unlike the GM or Ford diesels. It finds it's way into trailer rigs like beer trucks, etc. The most hostile environment that any engine can endure is in a marine application. You won't find any GM or Ford diesels there but LOTS of Cummins 5.9 and 6.7. Cummins is known for it's ease of serviceability and reliability. While you can get more HP/TQ out most any diesel, they are not designed for it and engine life will be shortened. Ask my neighbor about his 6.4 F350. Once you filter out the four letter words he was disappointed that he couldn't run up and down the hiway with the engine making 1000HP using a tuner and propane injection. He's on his third engine and the truck still doesn't have 100,000 miles on it. If you have the need for a diesel, buy the right truck to begin with and forget about getting more HP/TQ. Any F-500 will out pull an F350 anyday. It's all about application.

 

All 3 are going to follow these new strict emissions guidelines. The clean air regulations are going to become stricter at the beginning of 2010. I'm not really up to date on what Chevy's doing but that's actually another reason that Ford is coming out with the new 6.7 besides the problems they've had with navistar/international. Dodge is actually way ahead of the game since the 6.7 cummins was released near the end of 2006 i thiink. The Cummins 6.7 isn't as powerful as the 5.9 was, but that's the government putting retrictions on them. Fords new 6.7 will meet these guidelines also.

Here is a link to 5.9 vs 6.7 cummins...
http://www.dieselpowermag.com/tech/d...nes/index.html

 

The straight 6 design in diesels is the way they should be. All inline 6 engines are torque monsters, throw some boost into it and the sky is the limit.

 

Er what? International built the motors for industrial purposes, and sold some to Ford. DT444 and DT365. They're used in tow trucks, delivery trucks, etc. And if your neighbor ran propane in his 6.4, he deserves getting the motor blown up.

 

Yeah i know a few diesel mechanics. Internationals are in pretty much anything from tow trucks to delivery trucks and i think big rigs too. Not to offend anyone but they all say there crap too. That the cummins is def more reliable, among other positive aspects of it.
Personally tho, if i had the money it would come down between f250 and dodge 2500. Dodge can outpull the 250 i think, but i just love the styling of the F-250's. Perfect combo would be a 5.9 cummins in a 08 F250 or maybe ford's new 6.7. We'll have to wait and see.