Gas VS Diesel longevity

[DrDusty86]

My question is why does every post about gas vs diesel in pickup trucks that claim the newer diesels last MUCH longer?
I have yet to see a diesel running longer than the gas engine in the same truck that has been produced from any brand in the last 5 years and have not had $$$$ in repairs.
Case in point: my buddy's shop has a 08 Duramax with 200,000 miles that needs new DPF and water pump. That totals $3,600 for just 200k
His aunt has a 06 With a 6.0L gas that pulls nearly it's rated max and it is closing in on 272k. 2 water pumps and a starter

Seems to me the diesel will ONLY last longer if you dump huge amounts of money into it, where as the gas truck could still be going on the 2 cheaper water pumps and starter, factory injectors.............

Diesels lasting longer was a myth that should have died in 2003.
He has in his shop:
a 09 Dodge CR Cummins with 132K with a hole in the piston..no tuner
08 Duramax with 200k that needs emissions replacements and a water pump
a 09 ford 6.4 with the same issues as the Duramax..

A V10 would run well past 300k with proper care.

Why is the myth that diesels last much longer or oh, the gasser has 125k on it, it's going to need a rebuild soon still around?
Dusty

 

[JTK]

Dusty, I've got to agree with you there.

I know in my area, if a light truck's diesel engine hasn't worn out, the body and/or chassis has given up the ghost.

Maybe for massive amounts of heavy trailer towing they're an advantage, but everything else seems to be for the novelty factor.

Now for big OTR tractor use, yeah. Those babies are just broken in at 500Kmi.

Joel

 

[bullwinkle]

If you tow or haul a lot of weight, there is still a pretty big fuel savings-BUT, the newer & more emissions-laden the diesel, the more you'll have to stick into it over it's lifetime. Body durability depends on the chassis-for instance, I don't think I've ever seen a Dodge Ram plow truck that hasn't broken a frame sooner or later-but Ford-like my '89 7.3 F-Super Duty... well, I wouldn't want to see what would break the massive frame on that thing!

 

[Brons2]

There used to be a reliability advantage whe3n diesels had rotary pump injection and a relative lack of emission controls. But nowadays with COP ignition and fuel injection, it's hard to beat a gasser. Gasser emission controls are for sure more mature, proven and reliabile

As for the fuel costs, if a diesel will get better fuel mileage in your application, the payback vs. the inital higher acquisition cost is usually not going to show up in the first 100K.

The diesels I really like are the 4cyl small turbodiesels in passenger cars. I feel like they have a more usable torque curve at lower revs than a gasser, and they get better fuel milage. But alas they have not caught on here, other than on the Volkswagens.

 

[Spazdog]

Originally Posted By: bullwinkle
If you tow or haul a lot of weight, there is still a pretty big fuel savings-BUT, the newer & more emissions-laden the diesel, the more you'll have to stick into it over it's lifetime....


I think that's the primary problem.

The more emission control equipment, the more stuff breaks.

The B-series Cummins is used in lots of other equipment from Ford F-650s to Case farm equipment. You would expect durability out of equipment like that. But the OP cited an example of early death Dodge.

The 6.0 Powerstroke had a myriad of problems that the 7.3 did not experience. Usually premature 7.3 IH/Powerstroke death is operator related. I don't think it was just the "improved" emissions equipment that killed many of the 6.0s....It had other mechanical design faults. But I'm certain that the equipment didn't make matters any better.

Years ago, I had a girlfriend with a Rabbit diesel. More rust than car really. Taillight was smoked black and it could maybe hit 65mph at WOT. But it started and ran consistantly. It would shake like a paint mixer until all 4 cylinders got warm enough to light off the fuel on cold winter mornings, but it would start. The rest of the car was going to crumble into a pile of rust before that engine died.

 

[NHGUY]

The theory of a diesel lasting longer was due to the rugged construction (overbuilt) due to the high stress involved with the diesel cycle (20:1 compression),as opposed to a gas job that always seems to be designed "just rugged enough"...cast pistons/powdered connecting rods/thinwall block...

Also,diesels used sleeved engines,that could be fitted with new sleeves when a rebuild was needed.Crack/gouge a gas block and its over.

 

[DrDusty86]

So the only advantage to a new light truck diesel is pulling power?
The consensus is that it is not true by todays standards. Gas>diesel now for longevity?
I ask because I saw a post that a guy was getting a new CR Cummins in a 2500 series truck to haul a fish tank that weighs 4,000lbs saying " I do 80,000 miles a year, and the gasser would be worn out in 1.5 years" I think that a Hemi in a 2500 pulling just 4,000lbs will see 4-5 years easy with good care.

 

[Jim 5]

Originally Posted By: DrDusty86
So the only advantage to a new light truck diesel is pulling power?


I would say pulling power, and both loaded and unloaded fuel economy. I went from a gasser to a diesel for my RV tow vehicle and the all of those things improved.

One other factor is that diesels are worth more in the resale market, especially if they have higher miles. That resale may not pay off if you factor in the time value of money and the premium for the diesel engine.

On the other hand, if you're running it out to 300k miles, the difference in fuel economy and the time value of that money not spent on fuel should help.

 

[mechtech2]

Why/how does a water pump going bad at 200k condemn diesels?

 

[DrDusty86]

Because the water pump is $1600 For that price it aught to be good for 500k

 

[subiedriver]

Gasser pulling 5000 lbs at 11,000 feet in Colorado = worthless

Turbo diesel pulling 5000 lbs at 11,000 feet in Colorado = effortless with 40% better fuel economy.

You'd be amazed at what 20 psi of boost does at 11,000 feet.

The Cummins 5.9 in our '99 Dodge 2500 is good for 500,000 miles, although the truck probably isn't.

 

[rjundi]

Originally Posted By: subiedriver
Gasser pulling 5000 lbs at 11,000 feet in Colorado = worthless

Turbo diesel pulling 5000 lbs at 11,000 feet in Colorado = effortless with 40% better fuel economy.

You'd be amazed at what 20 psi of boost does at 11,000 feet.

The Cummins 5.9 in our '99 Dodge 2500 is good for 500,000 miles, although the truck probably isn't.


I agree however the majority of the buying population does not drive at 11,000 feet. Its a small minority. And yes gas engines pass through but they simply go slow over the pass and continue there merry way to lower elevation perfectly fine.

 

[subiedriver]

I'd like to see how long a 454 chevy would last with a steady diet of heavy pulling, vs a 5.9 Cummins.

 

[volk06]

To me most of the things you listed are maintenance and component related. Just because a water pump is bad doesn't mean the engine isn't going to last that long. The emission part once again is not an "engine" component and the DPF needs maintenance as they collect soot. They are high cost but that's something a diesel owner needs to consider. Most parts are engineered to last 250k. The fact of the matter is not many people keep a vehicle that long. Too me a only spending $1,600 on a vehicle that has almost 250k, is not too bad in reality if that's the only thing you've replaced, that's a lot of time and wear n tear.

If you pull as big of loads with a gasser, more than likely the diesel will always out pull, out run, and out last the gas engine in the same application.

In the end, the diesel engine will last a long time, its the other components that will needed replacing.

 

[Spazdog]

Originally Posted By: subiedriver
Gasser pulling 5000 lbs at 11,000 feet in Colorado = worthless

Turbo diesel pulling 5000 lbs at 11,000 feet in Colorado = effortless with 40% better fuel economy.

You'd be amazed at what 20 psi of boost does at 11,000 feet.

The Cummins 5.9 in our '99 Dodge 2500 is good for 500,000 miles, although the truck probably isn't.


You forgot EcoBoost at 11,000 feet.

Jury's still out on how long a turbo six lasts but I bet it does fairly well at high altitude.

 

[Shannow]

The diesel longevity story applies mostly to those engines that were in use when the story was created.

Large, C.I. blocks, C.I. heads, pre-chamber, low specific power outputs, and relatively massive internal architecture.

I've got concerns about the modern, high specific power output, alloy head, multiple injections per power stroke to achieve traditional diesel longevity.

With my Nissan turbodiesel, 110kW 3.0L, I've removed some of the stuff that has been attributed to early engine failures (blow-ups are relatively well known), I've put $14,500 approx of diesel through it.

Petrol version would be $19,000....however the savings could be wiped out with a single I.P. failure (also not uncommon).

However, the diesel power delivery (sans egr and swirl valve) is great, and I can pull 800km out of a tank on a long distance run versus 550 with petrol.

 

[DrDusty86]

GM 454's blow up at sea level..maaann thats not even fair.. I would say a 99' 24V 235hp/460ftlb Cummins vs a Ford V10 later..the better.. I think that the bearings and rings on a newer diesel are under more stress than the low power 500k-1m motors.
I think a V10 would outlive any current diesel even the 6.7 PSD, get the SAME milage as a factory 6.4PSD. And lord knows it could outlive a Common rail Cummins 6.7... my buddy calls new diesels from all brand "throw away" motors.

 

[subiedriver]

Yeah, but how much torque does the V-10 have at 1500 rpm? Our 5.9 Cummins peaks at 1500 rpm and holds its torque to 2500 rpm.

Plus, the V-10 will be getting 8 mpg, our '99 Cummins did 16.5 mpg last year, pulling a 2 quad trailer with a slide in camper, through mountainous terrain out here in Colorado. That's freakin good!

 

[ls1mike]

Originally Posted By: subiedriver
I'd like to see how long a 454 chevy would last with a steady diet of heavy pulling, vs a 5.9 Cummins.

Well my old 89 towed 7000 lbs for most of it's 180,000 miles with me and 9000 for the first 30,000 with the original owner who was a full timer. Maintenance is Key. The truck pulled a lot of passes in the Rockies at 3800 RPM going 45 miles an hour. I still see it as a friend of mine bought it. It has just shy of 230,000 on it now. Plus newer gas motors are much better than even the last GEN 454. I know of at least 2 guys that I personally camp with that have GM 6.0 gassers and both have over 200,000 miles on them a lot of that towing. 1 tows a 30 footer that comes in at 7800 loaded the other a 26 footer that is just shy of 7000 loaded.

Of course the Diesel will tow better and get mpg, but with the new stuff I think longevity is a question of maintenance and ecomonics. It just depends on how much you want to spend and what the ultimate goal is.

 

[subiedriver]

I will say that my situation is unique, living out here in Colorado and towing at altitude pretty much requires a diesel for good performance. Getting to our favorite riding area's often involves several 11,000 foot passes and the average altitude over the whole trip will be about 9000 feet.

We used to have a 5.4 F-150 and putting the camper and quads on it, then driving over these passes put a serious hurt on that thing, dragged it down to 35 mph, screaming for mercy at 4000 rpm.