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Duramax Diesel vs. V6 Gas Engine - 100K Fuel Cost Comparo


Gorehamj

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Bottom line is that you need to keep the Diesel for 3 more years to get even money out of it ~vs~ a gas truck, Cost to own and operate recovered. If you have "real use" for the Diesel, as in Need the Torque, it could be worth it. Its a good gamble for4 GM as people tend to keep "full size" trucks longer than cars. I am unsure if the med size trucks are held as long though.. The small Chevy LUV ( Isuzu) was a available as a small "Duramax" ( Isuzu / GM partnership is the father of the Duramax) I note there are many countries with mini trucks with diesels, and even VW had a truck like vehicle which I think had a diesel option. Interesting Topic..

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Cowpie, you are indeed missing beejay's entire point. You continue to say "go and price a replacement for x unit". Well of course that price is going to be off the charts because it is retail. You can price anything for a gasoline engine and it too would be off the charts. If you took every single part of a car and priced it at retail, a Cruz would cost you $150k!!! I was looking at a car a month back that was a turbo gasoline. Complaints from people about the car were that the turbo is almost always going to go at a given mileage number and that the repair was like $3k. This wasn't even for a diesel either.

 

The point is that the engine and other emission goodies on a mass scale at the manufacturer price level does not cost $4,000 more than a similar equipped gasoline setup. Mind you, we're not talking $4k total at the mfg level, we're talking $4k MORE. Part of that extra amount is no doubt because of the numbers being produced. However, if you offered the consumer the option of the diesel for a grand more or close to the same, they would be flying out of the lots.

Exactly!

The mfr's could easily sell the 2.8 for 1-2k more than the gasser & they'd make huge profits as well as selling every one they can build & more.

Instead, the diesels are always priced such that only a very tiny percentage of the population can truly get any $$$ benefit of ownership from them. This makes no sense from a value proposition standpoint & is why I suspect it's possible that mfr's are using pricing to discourage most buyers from purchasing diesels. On the surface that wouldn't make sense, but if the EPA is involved, it could make perfect sense....

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I would avoid the diesel for reliability reasons. Maybe it will "run forever" but will it get you all the way to your destination every time. Maybe after a few years of recalls, revised motor mounts, fuel pump failures, def problems and other random teething problems it could make sense. I see the advantage of the diesel being a V8 replacement. I would still rather have a V8 in a crewcab truck midsize or fullsize.

Lot of good a diesel engine does when the chassis and electrical can't make it past year 12.

 

There's a '02 Duramax 2500HD with 225k miles sitting in my backyard. It left my brother dead on the side of the road 4 hours west of here in NY state. Luckily I have a flatbed trailer, or the tow would've cost him $1,100!!

 

Somewhere in the billion miles of wiring in this electronic wonder is a intermittent dead short. Good luck trying to find that one! In addition to that, the cab corners and rocker panels are pretty much gone. Hitch and spare tire had to be removed before they ended up in someone's windshield on the highway. Rear bumper has already been replaced.

 

My ol' man bought this thing for $40 LARGE back in '01. Always washed and waxed it, and took care of it with regular maintenance. Of course, GM's poorly engineered components failed several times over that time frame (injectors for one - on it's 4th set!!)

 

My brother sunk over $20k into this thing modifying the engine and transmission. The thing hauls ass! Now we can't give it away.

 

So much for longevity.

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look, you guys really need broaden your perspectives. Even diesel vs gas UTV's, the diesels are 2-3K more than gas versions. If just plain costs more to make a diesel motor. The internals are different and the volume number of motors built for a particular vehicle or piece of equipment like a UTV are very much in favor of gassers. Like the John Deere dealer near me. They sell 10 to 1 gas to diesel varieties of their Gator UTV's , and even have some trade their diesel version in for gas. And this is a large agriculture related JD dealer with a dozen locations out here in farm and cattle country and not some small commercial and property owner type of dealership that caters to more metro type users and sportsman. Their major customer base is farmers and ranchers, who have an appreciation for diesel power. When it comes to on the road vehicles, it is going to be as much or more of a spread in the number of gas powered Colorados than diesel. Costs to build always get cheaper in higher volume production. the Gasser will always have that edge. And we are not even into the emissions junk part of the equation. It is just simple economics of scale.

 

Diesels have generally had a better retention of value on resale, but that is for the heavy duty pickups. That may not hold true for the Colorado. It sure didn't for the Jeep Liberty Diesel. The buyers are very different. And as with all things, the value of something is purely dependent on the number of folks who want them. Like the previous post... sometimes you just can't give them away. All depends on who is looking to buy and who is actually buying.

 

Resale on a vehicle is a very lame reason to buy one. Markets change quickly and there are a myriad things that can change the consumer demand for something. For instance, with the advent of all the emission stuff on vehicles from autos to heavy commercial trucks, I have no desire to buy anyone else's used problems. I got burned on a Cummins ISX in a semi doing that. Now, I will only buy new. The used commercial truck market is in a serious slump. No one wants to buy used trucks that have a high risk of needing major repairs to emissions junk in a short time frame. And one may delete all of that stuff and reprogram the pickup, but that limits even more the number of available buyers. Serious diesel pickup owners are less likely to buy someone's diesel pickup that they did all kinds of aftermarket stuff to in an attempt to make up for a limited testosterone level. There could be a dozen nice looking used diesel pickups at a dealership, but I would only buy new. Before all this emission stuff, that would not be true. All that has changed for many pickups and commercial truck buyers. Only those that have very limited experience with diesel trucks will be tempted to buy someone elses used stuff.

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Gotta defend my brother there. He built it because it was fun. Plain and simple. GM built a piece of shit that could barely handle a decade of northern driving. End of story.

 

I'm still trying to figure out how any manufacturer can sell new. Unless you work the thing every second of its short life, it's just not worth it. If you run them, they break & rust. If you let 'em sit, they break & rust. Not many can afford a climate controlled garage to park it in whenever it rains or snows, so you're pretty much f'ed no matter how you slice it. That's not even factoring in the driveline - don't much matter if it's gas or diesel if it can't make it 10 years before body panels and brake lines blow out.

 

I'm done playing that game. Next truck I'll build myself. When I get too old to build them, maybe I'll buy a horse.

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look, you guys really need broaden your perspectives. Even diesel vs gas UTV's, the diesels are 2-3K more than gas versions. If just plain costs more to make a diesel motor. The internals are different and the volume number of motors built for a particular vehicle or piece of equipment like a UTV are very much in favor of gassers. Like the John Deere dealer near me. They sell 10 to 1 gas to diesel varieties of their Gator UTV's , and even have some trade their diesel version in for gas. And this is a large agriculture related JD dealer with a dozen locations out here in farm and cattle country and not some small commercial and property owner type of dealership that caters to more metro type users and sportsman. Their major customer base is farmers and ranchers, who have an appreciation for diesel power. When it comes to on the road vehicles, it is going to be as much or more of a spread in the number of gas powered Colorados than diesel. Costs to build always get cheaper in higher volume production. the Gasser will always have that edge. And we are not even into the emissions junk part of the equation. It is just simple economics of scale.

 

Diesels have generally had a better retention of value on resale, but that is for the heavy duty pickups. That may not hold true for the Colorado. It sure didn't for the Jeep Liberty Diesel. The buyers are very different. And as with all things, the value of something is purely dependent on the number of folks who want them. Like the previous post... sometimes you just can't give them away. All depends on who is looking to buy and who is actually buying.

 

Resale on a vehicle is a very lame reason to buy one. Markets change quickly and there are a myriad things that can change the consumer demand for something. For instance, with the advent of all the emission stuff on vehicles from autos to heavy commercial trucks, I have no desire to buy anyone else's used problems. I got burned on a Cummins ISX in a semi doing that. Now, I will only buy new. The used commercial truck market is in a serious slump. No one wants to buy used trucks that have a high risk of needing major repairs to emissions junk in a short time frame. And one may delete all of that stuff and reprogram the pickup, but that limits even more the number of available buyers. Serious diesel pickup owners are less likely to buy someone's diesel pickup that they did all kinds of aftermarket stuff to in an attempt to make up for a limited testosterone level. There could be a dozen nice looking used diesel pickups at a dealership, but I would only buy new. Before all this emission stuff, that would not be true. All that has changed for many pickups and commercial truck buyers. Only those that have very limited experience with diesel trucks will be tempted to buy someone elses used stuff.

You still don't get it. It's clear you really don't have a manufacturing background, or an understanding of that, so let me explain again to you why it only costs a small amount more to build a diesel than a gasser; Let's use a small automotive style 4 cyl turbo direct injected engine with balance shaft for comparison, as this engine config is avail in both versions in large volumes.

 

Lets assume both are the same size and going to be built in similar large volumes exceeding 100k units annually.

The diesel blocks will likely have a few extra pounds of metal in them (& I mean a 'few') to beef up key places around the crank etc. Aluminum and steel bought on an industrial scale cost well under a dollar per pound.

This will add literally a few dollars in cost to the block, as the casting, machining and finishing & assembly processes have no difference in costs between the two types. Same goes for the heads and internals; Pistons, rods, crank etc. Worst case, maybe $100-$150 total difference on the absolute outside for this size of engine. The difference in cost is really the extra weight of the diesel. Diesel engines in this size tend not to use wet sleeves like large commercial diesels do, which I have mentioned more than once have really nothing to do with this issue, yet you keep hanging onto it for some reason.

If both engines are using aluminum blocks, they will both have pressed in iron/steel sleeves. Same cost.

All other parts for the engine; bolts, valves, cams, springs,Turbos, intakes, exhaust manifolds, etc. ancilliary items, pulleys, belts etc. etc. costs the same, as they are essentially the same and use pretty much the same numbers of items.

Injection pumps are a bit more robust for the diesel, so they might cost about $100 more to manufacture, compared to the gas version.

They both use roughly similar exhaust layouts with cats, sensors etc made from stainless. The diesel will be a few dollars more to manufacture as it is usually a bit bigger- say $50. Diesel will have an extra section to deal with soot etc, plus a def system, but they only add a few hundred in total manufacturing and assembly costs max. Lets be generous and say $500.

The rest of the drive line is essentially the same between the two.

The diesel doesn't need a fancy wiring harness etc for ignition etc., but the gasser does. Subtract $100 in manufacturing and assembly.

The gasser needs an evap and carbon filter system, which the diesel doesn't. Subtract another say $100 in manufacturing and assembly.

So what are we at for a total cost difference between diesel and gas now? $600....

 

Yet they want $3500??

 

As I mentioned before, they would easily sell similar numbers of the 2.8 diesels to the gassers, if they priced them realistically based on actual manufacturing costs. The economies of scale would easily be met.

I'd easily and gladly buy a diesel(along with many thousands of other truck buyers) if the cost premium over the base 4 was under 2gs, but they've priced it to prevent all but the most hardcore folks from buying it.

Why is that?

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Except the block on the 2.8L is cast iron with wet sleeve design. And you forgot the water cooled variable geometry turbo, which has a substantial cost over a non VG or waste gated turbo, none of which the gasser has. And the gasser does not require SCR and DPF emissions units, including extra lines and injectors for DEF and fuel for DPF regeneration. The gasser in the Colorado has none of this stuff and features. The 2.8L Dmax is produced on a much more limited scale for two little pickups compared the 3.6L, which is a common V6 across several GM platforms. And we haven't even mentioned the intercooler setup that, yet again, the gasser does not have. And you failed to consider the common rail system of the diesel, which requires a fuel return to the tank unlike the gasser. And also unlike the gasser which has a electric fuel pump in the tank, the diesel has a on engine fuel pump to supply the injectors, and probably a lift pump between tank and fuel filter to provide ample fuel from the tank to keep flow thru the sizable fuel filter and provide ample supply to the on engine fuel pump.

 

And yes, the 2.8L Dmax, which is based on the VM 2.8L is wet sleeved. The VM 2.8L I owned was indeed wet sleeved, I can provide the manufacturer literature on it. So your contention that no engine of this size is wet sleeved is in error. The chief engineer for the 2.8L Dmax was one of the engineers at VM when GM still had a 50% stake in that company until 2013, and started working on the 2.8L Dmax for GM before GM sold off it's share. It is a simple updating of an already existent motor with a long track record. Chief engineer on this project is Nicola Menarini who came over from VM, after he started the project there.

 

You are being really disingenuous in your example You mention comparing a typical turbo charged 4 cylinder to this one. The comparison in cost is between the 3.6L V6 in the Colorado to the 2.8L Dmax in the Colorado. You are accusing me of something you have a problem with... you don't get it.

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Except the block on the 2.8L is cast iron with wet sleeve design. And you forgot the water cooled variable geometry turbo, which has a substantial cost over a non VG or waste gated turbo, none of which the gasser has. And the gasser does not require SCR and DPF emissions units, including extra lines and injectors for DEF and fuel for DPF regeneration. The gasser in the Colorado has none of this stuff and features. The 2.8L Dmax is produced on a much more limited scale for two little pickups compared the 3.6L, which is a common V6 across several GM platforms. And we haven't even mentioned the intercooler setup that, yet again, the gasser does not have. And you failed to consider the common rail system of the diesel, which requires a fuel return to the tank unlike the gasser. And also unlike the gasser which has a electric fuel pump in the tank, the diesel has a on engine fuel pump to supply the injectors, and probably a lift pump between tank and fuel filter to provide ample fuel from the tank to keep flow thru the sizable fuel filter and provide ample supply to the on engine fuel pump.

 

And yes, the 2.8L Dmax, which is based on the VM 2.8L is wet sleeved. The VM 2.8L I owned was indeed wet sleeved, I can provide the manufacturer literature on it. So your contention that no engine of this size is wet sleeved is in error. The chief engineer for the 2.8L Dmax was one of the engineers at VM when GM still had a 50% stake in that company until 2013, and started working on the 2.8L Dmax for GM before GM sold off it's share. It is a simple updating of an already existent motor with a long track record. Chief engineer on this project is Nicola Menarini who came over from VM, after he started the project there.

 

You are being really disingenuous in your example You mention comparing a typical turbo charged 4 cylinder to this one. The comparison in cost is between the 3.6L V6 in the Colorado to the 2.8L Dmax in the Colorado. You are accusing me of something you have a problem with... you don't get it.

Maybe my wording was bad or.....Perhaps you should work on your reading comprehension and go back and re-read my last post very thoroughly, with a copy of websters or the oxford dictionary handy.

 

I said small diesels tend not to be wet sleeved.(do you understand what the section in bold means?) Even if this one is, it doesn't add much in the way of costs, maybe $100 in manufacturing costs at most.

I didn't forget anything about the turbo, you misread my post.

I accounted for the SCR and DPF - go back and re-read my post

Scale was addressed in my example. Go back and re-read my post. Besides the 2.8 minimax is sold in much higher quantities elsewhere around the world, so it has economies of scale.

Injection pump- go back and re-read my post. Besides, direct injected gassers need way stronger pumps than the old port and TB injected versions, They're running at a hundred times or more the pressures they used to.

Fuel pumps - almost a non-issue.

Regarding intercoolers- assume both HYPOTHETICAL engines are the same.

Fuel return? most, if not all gas engines have a fuel return. Even carbureted cars used to have them. Not that it matters much, as its only a few dollars to make.

 

Regarding your last paragraph- go back and re-read my first and the first sentence of the second..I was drawing a HYPOTHETICAL example. Go look up the meaning of hypothetical......

 

 

 

I hypothetically demonstrated to you a cost comparison between two similar sized small 4cyl engines and then used that to show you that perhaps the real life 2.8 might be overpriced in these trucks. Yet somehow you missed all that & missed the point of most or all of what I wrote, then responded with a different argument. You're also not getting that the parts differences in the two real life engines doesn't make much difference from a cost standpoint. You also keep arguing from a retail standpoint, without understanding the real costs to actually produce those parts.

 

It's good to know that you're contentedly happy to always overpay.

 

We can go around and around at this ad infinitum, but at the end of the day a diesel doesn't cost near the huge premium they charge the customer for it. It just doesn't. You need to accept that and move on.

Jus sayin'

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Gotta defend my brother there. He built it because it was fun. Plain and simple. GM built a piece of shit that could barely handle a decade of northern driving. End of story.

 

I'm still trying to figure out how any manufacturer can sell new. Unless you work the thing every second of its short life, it's just not worth it. If you run them, they break & rust. If you let 'em sit, they break & rust. Not many can afford a climate controlled garage to park it in whenever it rains or snows, so you're pretty much f'ed no matter how you slice it. That's not even factoring in the driveline - don't much matter if it's gas or diesel if it can't make it 10 years before body panels and brake lines blow out.

 

I'm done playing that game. Next truck I'll build myself. When I get too old to build them, maybe I'll buy a horse.

How much for that dmax in your backyard? I'll take that problem off your hands for the right price

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He's got a lot into it, so it's going to be high. Make an offer & I'll let you know.

 

I can deliver as well, but that's going to be high too considering I'll be hauling this with a 1/2 ton pickup. Figure on $1.30 a mile from Worcester, MA as a rough estimate.

 

Here's a list of what he can remember:

 

 

Big dipper trans, ML converter with 35,000mi (just flushed to Quatrasyn)
Pump rub fixed
Injectors done (all new lines too) @ 190k
30% over tips last year
Airdog 165 on top of Nictane adapter with CAT Ultra high filter (all done with injectors)
ARP Headstuds, headgaskets fresh last year
Fresh LBZ CP3
SS brake lines tip to tail, along with complete brake job
Industrial Injection Silverbullet Phatshaft 66mm
Fresh U-joints and balanced shaft
Welded waterpump with new cover
Fresh Powersteering pump and lines
All coolant hoses fresh
All front suspension wear parts new last spring (ball joints, tie rods, pitman, idler and idler shaft)
Bilstein 5100 front & rear
MBRP intercooler pipes
4" exhaust turbo back (various brands, all stainless (needs muffler or straight pipe)
Volant Powercore intake
All Amsoil fluids and filters (except Allison - stock only)
Super 5th mounting plates (no hitch)
Ridgerunner Moonshine EFI
Interior decent, showing age
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I've been a loyal Chevrolet truck and Camaro customer for 40 years.One thing that's a huge factor I think is being missed is that a diesel motor can drive significantly farther than a gas motor. I'm not going to say that I can dogmatically prove that this motor 2.8 liter Diesel that's going into the Colorado can compare with the longevity of a 6.6 L Duramax diesel motor because there are none that have been around long enough to know that for sure.

 

But if this new 4.0 liter diesel engine can drive as far as the Duramax 400-500k miles before a major repairs need to be done that's a huge cost saving factor. We all know that when you finance a vehicle the dealership and the finance company the interest is always paid first let's just say 3 1/2 years in the 72 month loan by the time you pay off your gas powered vehicle between 100k miles it has lost a significant amount of value.

 

This is not true of diesel motors Which at 100,000 miles have just barely been broken in and are finally starting to get optimum fuel economy.

 

I have found that any of my Chevy diesel trucks maintain the value and keep the owner in a good equity situation should you ever need to sell the truck.

 

Lastly gas prices are going to go back to the way they were before and possibly significantly higher.If you look at historical data and future projections for energy prices around the world don't expect for them to go down there is just way too much money involved in worldwide energy monopolies and because of that I certainly think that a diesel motor makes a lot of sense even if you don't tow thing.

 

With the gas truck the dealership and the finance company always wins with the diesel truck puts the odds back in our favor.

 

 

 

 

 

 

 

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