3/4 ton diesels

[IB Adrian]

Now I know this has been thrashed to death on this forum but... I would like a complete understanding of what everyone thinks here of the 6.0PSD and its competition (we in Oz get none of these engines, we only get the 7.3l PSD) My understanding thus far: Cummins: Pros: Arguably the most durable engine, Cummins reputation, simple straight 6 design, lots of low down torque, prehaps the best engine/manual trans combo, so far the most successful engine for modding for truck pulls, highest stock torque figures, and equal highest power figures Cons: Design outdated, far and away the slowest of the 3 engines, torque curve drops considerably at higher rpm, mated with very average auto trans, engine likely to be replaced soon, Its a Dodge Duramax: Pros: Quite a high tech design, works very well at higher rpm, largest capacity engine, gets a proven Allison transmission, very good for modding for truck pulls, reports are it is quite a reliable engine Cons: Previous GM diesels tarnish reputation, Isuzu an unkown quantity in the Amercan truck market, Allison transmission now quite dated, Aluminium heads are questionable for long term reliablity, not enough low rpm torque PSD: Pros: The most high tech diesel, gains strong 7.3l PSD AND Ford reputation, the fastest stock truck, the best auto transmission, the flattest torque curve Cons: Early teething issues have tarnished reputation, the hardest truck to mod for truck pulls, lowest quoted power and torque figures. From this I rate PSD number 1, Duramax a close number 2, Cummins a distant 3rd What am I missing? What are your thoughts? Also I believe all engines have similar fuel consumption, am I correct?

[FORD352V8]

its not bad but I warn you are opening a huge can of worms here theres gonna be some serious flaming. I prefer my 7.3L over the 6.0L does not have a low-end. The 7.3L is excellent and I think its better then the 6.0L Sure its a little slower but a little more air in and out and that story changes. Low-end torqe is what counts for towing, but most HD truck buyers do not use there trucks for HD towing mostly for grocery getting and maybe a trialer to haul ATV's. That said the Cummins is a dog. The only way the Cummins could be competive is if it had 8 gears minium. They are great in OTR trucks but those trucks got 10 speeds and 18 speeds. The power band is too small on the cummins. I have not seen anyone bash the 7.3L until the 6.0L came out. So it doseant do zero to sixty in 7 seconds and now it sucks right? The 7.3L is a better towing engine hands down!

[IB Tim]

Snap-pop-woooooosh, that was the can of worms opening...
Let us keep this on nice

[DMAX-HD]

Bigf350,

You've hit a couple things right on the head a couple others could go either way(comment of Allison being dated and Isuzu being an unknown). My personal feeling is that either of the V designs are fine (Ford or GM) especially for hwy towing. If I was seriously in the market it'd sure be hard to look past Fords '05 model O but Chevy just up'ed tq to 605 f/lbs. So confusing...

But having had a 7.3 litre before the D/A I can tell you it really doesn't compare to the 6'o or the Dmax - performance wise. Great motor though never gave me a lick of problems.

[DMAX-HD]

I didn't read the fuel consumption part. From what I read. Pulling load all 3 seem to be the same. Empty the DMax appears to do a lil better (18-19) cept in the winter - all bets are off.

Also for 1 of your pros for the Dmax is really meant for the PSD 'works better @ higher RPM's'. The PSD actaully has the higher RPM. Like the Aluminum heads of the Dmax - that could be a pro or a con only time will tell. Also GM addressed the the tq coming on to late and moved it lower in the powerband to 1600 RPM's some time ago vs. the intitial 1800 RPM. The tq curve between the 2 is very close.

1 other thing we always bicker about is SFA vs. IFS. Pros and cons to both - if you do a search you dig up that nasty lil thread too. I'm torn - I want both - if it were possible.

[IB Adrian]

Originally Posted by DMAX-HD

Bigf350,

You've hit a couple things right on the head a couple others could go either way(comment of Allison being dated and Isuzu being an unknown).

The reason I put the Allison being dated, is that is what I am told compared to the Torqshift...
As for Isuzu being an unknown, I only stated that in the American truck market, us down in Oz have had Isuzu making Trucks for years (my old man had one that gave no trouble for 400 000km), so not saying they can't build Diesels, just saying they are yet to earn a reputation like Navistar and Cummins in the States.

[jroehl]

Just to clarify a little about Isuzu. I don't know about other parts of the country, but I sure see alot of Isuzu diesel box trucks around. Granted, it's not the same as the engine they put in 3/4- and 1-ton trucks for heavy haulin' and towin', but they've been around a while as delivery trucks. Anyone know what the engine they use is?

Jason

[FERacing66]

izuzu does make good motors. No doubt about that. They are only forign to Americans. People around the world use them and they are relaiable.

[DMAX-HD]

Another thing I noticed is your name being BIG350. And this is 1 thing that really erks me about the GM offering is if you get a 1 ton it has to be the dully. They don't make a 1 ton that isn't a dully. That turns a lot of folks off right away.

[aketay]

Originally Posted by DMAX-HD

Another thing I noticed is your name being BIG350. And this is 1 thing that really erks me about the GM offering is if you get a 1 ton it has to be the dully. They don't make a 1 ton that isn't a dully. That turns a lot of folks off right away.

They do make a SRW 1-ton, long-bed only..mostly fleet vehicles and very hard to find.

[racsan]

i havent driven any of the diesels, but back in '86 dad bought a new f250 std cab 2wd with the 6.9 navastar with the creeper - first 4 spd. we had nothing but problems with that truck. glow plugs burning out, injecter pump tuning, would get good fuel milage but have no power, had dealer turn it up, ran like a 460 but drank the fuel and fogged for mosquitos, twice i had the shifter come up out of the trans when i was going from 2nd to 3rd, and it wound up in reverse. would get stuck on wet grass, all that engine weight up front and not enough chassis weight for the rear axle. had to be plugged in overnight if temperture dropped below 45. was a real hot-rod with the pump turned up and empty, but a real dissapointment as a truck. im a ford fan through and through but i beleive this one was a real fowled over rebuilt dodge. we traded it in with only 12,000 miles for a new '89 bronco. and dad swore he'd never have another diesel pickup. personally, id like to have the ford chassis, with the cummins engine, and even though im pro-stick shift, the allison automatic. anyone else have a problematic 6.9?

[bodabdan]

Big350-

I noticed that you mentioned truck pulls a couple of times. I can't speak first hand but I have been a gearhead long enough to know that if you are buying a truck to pull with, any truck that you mentioned could be made to work with the right amount of $$$.
IMO I think that the peak hp/torque numbers are not nearly as important as the overall torque and hp curve. What good is peak power at 3000 rpm if you can't get the motor up to 3000 with a load?
I own a 7.3 so I can't speak first hand much about the 6.0. I can tell you though that there were some major and minor bugs when the 6.0 came out, but most of the bugs can be addressed by your dealer. The current 6.0 is a good motor. The Ford is a good truck, as is the Dodge and the Chevy. I really don't believe that any of the big 3 make junk.
As far as Isuzu making engines, I am uncomfortable with their motors in American products but that doesn't mean it's not good, I'm just stubborn that way. Mercury marine made the engines for the ZR-1 corvette, and that worked pretty well.

[IB Adrian]

Originally Posted by bodabdan

I have been a gearhead long enough to know that if you are buying a truck to pull with, any truck that you mentioned could be made to work with the right amount of $$$.

Yeah I agree with you, but
I am of the understanding the PSD is the hardest and the most expensive of the 3 engines to be a really good truck pull competitor.

[FordLariat]

I have heard that the PSD does very well in the truck pulls, so it may not be as hard to mod as you would think.

[IB Tim]

Does any body realy pull with a stock truck at those races?