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Discussion Starter · #1 ·
I have GMC SLE ext Short Box with a 5.3l engine
I have a cap and ladders on top and carry tools and equipment in the back. Need the size more for volume than weight.
Why does not GM make a small diesal engine that could 30 mpg.
I put on about 50000 km per year so it would be nice to get some good mileage out of the truck.
If I need speed I take the wifes STS for a drive
 

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;) Hi this is Louischevy, i second that, i to wish GM would offer a V6 Duramax for the 1500 series Chevy/ GMC. I have read some where that GM is working on a V6 Dieasel and so is Ford. :rolleyes:
 

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Ford had Navistar designing a V6 PowerSmoke, but they pulled out after a lot of work had been done, and ended up having to pay Navistar a considerable amount of money for their development costs that they were now not going to recover with manufacturing the engines. I think Ford got cold feet about costs and emission regulations.

GM has done some development on a V6 Duramax, but there are no production plans for it, probably for the same reasons sited for Ford.
 

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The question is how many people would opt for a V6 diesel in a pickup or SUV when it'd likely be a $2-3K premium? 30mpg is a stretch in a full-size pickup, 23 is more like it. At a 3mpg increase it would take over 100,000 miles to break even on the premium paid. Furthermore, the general (light-use) market still has cold feet about diesels. Where are diesels finding success? In Europe, where gasoline is so expensive, the payback on the diesel premium is much shorter. In the U.S., heavy-duty pickup buyers value the extra low-end torque of diesels. Any gain in efficiency is a bonus. I'd love to see something like a Colorado offered with the rumble and grunt of a diesel, and I'd be one to spend extra money on it... but I'm not sure the overall market reception would make it a good case.
 

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Originally posted by desmo9@Feb 25 2004, 07:33 PM
The question is how many people would opt for a V6 diesel in a pickup or SUV when it'd likely be a $2-3K premium? 30mpg is a stretch in a full-size pickup, 23 is more like it.
30 wouldn't be too far off or unreasonable. A 1 ton (2500HD/3500) Duramax can do low 20s right now. For a lighter truck with 2 less cylinders, I don't think 30 is a unrealistic stretch. High 20s definetly wouldn't be. Who'd pay the premium? I'd jump at it in a heartbeat.

As a matter of fact, if any of the present truckmakers offered a modern diesel in their 15x series trucks right now, I bet it'd be a extremely hot seller. I've seen posts about this very subject in other truck forums and many guys are waiting for this to happen.
 

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Weight of a truck has almost no bearing on highway mpg, where the low-20s figure comes into play. Aerodynamics, rolling resistance, and gearing are about it. The frontal area and drag coefficient of a half-ton is not much different than a 3/4 or 1-ton, so I still don't see a 40% gain. Energy/gallon of diesel, going by memory here, is about 10-15% greater than for gasoline. So everything else being equal, if a 1 ton can achieve 20mpg, I don't know how a half-ton could do much better than low-mid 20s'. Maybe 25 for a 2WD. V6 thermal efficiency would not be too much better than a V8, so not a huge gain there. Would have to run the numbers.

I'd concur, though, that if you could eke out 8-10 extra mpg on a light-duty truck, there would be a good case for doing it.. with the expectation that people would pay for it.
 

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Actually, I think you have it backwards. IIRC, Diesel has more energy per gallon than gasoline. Perhaps you're thinking propane?

Since the diesel engine - even a V6 - would be working less with the same gearing as a gasoline engine, it will sip substantially less fuel on the highway.

The Duramax/8.1 is a good practicle example of this. A 3.73 geared Duramax (the standard ratio in a 2500HD/3500) and a 8.1 with the Allison tranny will easily get 7-8 mpg better on the highway than the big block with comparable gearing.
 

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I meant it the way you said it... diesel has greater energy/volume than gasoline. Sorry if my wording was unclear.

I'm not sure about the "working hard" thing, because the torque needed to push the vehicle down the road at a given speed is the same. I suppose you're saying that a diesel can operate at a lower point on the BSFC curve on-highway, which may be true.

One factor I did leave out, though, which adds another couple mpg in diesels favor, is efficiency. If memory serves, there is another few percentage point gain in efficiency (how much fuel energy is coverted into "go" energy), due mainly to higher compression ratio. Add this to the 15%-ish gain in energy per gallon.

It does seem like a smaller diesel in a half ton would be marketable, if for nothing else the torque spread and to Peterbilt soundtrack. But are these guys willing to pay $3-4 grand for it? The gas V8s are no slouch.
 

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Originally posted by desmo9@Feb 27 2004, 06:57 PM
It does seem like a smaller diesel in a half ton would be marketable, if for nothing else the torque spread and to Peterbilt soundtrack. But are these guys willing to pay $3-4 grand for it? The gas V8s are no slouch.
You're right :) Gas engines are great, but they are still so thirsty its almost ridiculous at times. The mfgs haven't pushed fuel economy developments on them because they haven't needed to, as opposed to autos where they are forced by the government and look how far they've gone. It's now commonplace for 35-40MPG mid size cars. Trucks have hardly changed at all - a person is lucky to get 20MPG on the highway with a 15x series! I don't think anyone would say that a truck should get the same fuel economy as a car, but I don't think there would be much arguement that they could be better than they are now, and diesel is a great fix - fantastic power and inherently more effecient.

I bet if they did price it accordingly - say a $2K-3K premium they would sell - and strongly at that.

Since Trucks are pretty much universally regarded as the "margin makers" for the big 3, they could probably afford to even eat a bit of the cost if necessary... even though I'm sure they wouldn't want to.
 

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the DodgeBenz Sprinter van with five cylinder diesel gets 30 mpg,
I dont see why small pickup couldnt get at least that !

hey GM just build it! and we will buy it! :D
 

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Discussion Starter · #11 ·
the DodgeBenz Sprinter van with five cylinder diesel gets 30 mpg,
I dont see why small pickup couldnt get at least that
And it is like a big box
I agree built it amd we will buy it
 

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Ford hasn't backed out of a small diesel for their 1/2 tons yet. Just backed away from the 4.5l V6 International. They still have plans to be the first out with a small diesel for their 1/2tons

Emissions are what killed the cornbiner, I don't know who will build it but there will be a diesel since they have 7700lb GVWR 1/2 ton already. verses GM at 6800lb GVWR.

Also theres a rumour bout a 6.4L twin turbo to replace the 6.0L Powerstroke.
 

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Diesel Engines make a lot of practical sense in today’s economy. First, regardless of fuel price, they help to conserve fuel. Second, with low sulfur fuel on the way in 2006 and improved injection from Bosch and others, emissions are approaching that of hybrids and even fuel cells. Third, with larger demand for Diesels, the cost difference at purchase with diminish. Fourth, life cycle cost and maintenance for diesels is lower than gas engines. Fifth, with more passenger usage, filling stations could offer Diesel without the "Big Rig" Road Tax improving cost to own.

Hence, the case for diesels is immediate. There are still bumps in the road with emissions and environmental disconnects in states like ME and CA, but this is a short term issue. In the next three years look to DaimlerChrysler (DC) to be a leader in Diesels technology and applications.

GM is bypassing Diesels for Hybrid Electrics starting in 2006. If you think people won't embrace Diesels, they certainly won't embrace Hybrid Electrics. This is part of the plan to evolve into Fuel Cells and the Hydrogen Economy. GM has lost touch with reality and quite possibly physics.

Let's hope DaimlerChrysler will see its way clear to build a Suburban'esq vehicle based upon the Ram chassis with a Cummins Diesel. Even the new Jeep Grand Cherokee to debut at the NY show in April 2004 will support a new DC Diesel.

Bottom line: I'm tired of waiting for GM to meet my needs. It's time to move on!
 

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Originally posted by otisunimog@Mar 16 2004, 03:35 PM
Diesel Engines make a lot of practical sense in today’s economy. First, regardless of fuel price, they help to conserve fuel. Second, with low sulfur fuel on the way in 2006 and improved injection from Bosch and others, emissions are approaching that of hybrids and even fuel cells. Third, with larger demand for Diesels, the cost difference at purchase with diminish. Fourth, life cycle cost and maintenance for diesels is lower than gas engines. Fifth, with more passenger usage, filling stations could offer Diesel without the "Big Rig" Road Tax improving cost to own.

I agree with most of your points, but I have to question your third and fourth ones.
I'm not sure that additional volume will help that much with the purchase cost of diesels. With their compression ratios, they must be built much heavier than gas engines, and I don't see additional volume bringing that down much. Plus there will always be the expense of the turbo, since it doesn't make sense to build a diesel without one.

As for maintenance being less on diesels, I have to wonder about that too. Gas engines don't need much of anything these days, just spark plugs and maybe wires around 100K. Diesel oil changes are typically more frequent and require much more oil, plus fuel filtering is more rigorous and costly. Back in the days of gas engines needing plugs, points, condensor and more every 30K, diesels definitely had an advantage here.

But I'd like to see some light-duty diesel choices too. I had a 1982 Blazer with a 6.2L diesel, and enjoyed averaging around 20 mpg, with 22-23 on the highway, and 600 miles per tank.
 

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Its a total goverment thing with the emission regulations being different it the under 8500lb GVWR catigory.
I would gladly pay a $3-5000 premium for a diesel in a light duty truck, I do not put on alot of mile but my truck does put on alot of hours idling or at a slow speed, and pushes heavy loads. This is where a diesel is much more effient than a gasoline engine,
Case in point- a friend had sunk his truck through the ice and I went to help pull it out. My truck (1/2 ton 350 V8) and a 5.9L cummins sat idling all day on the ice, My friend of course filled us both up at the end of the day. $30.00 in my truck verse $5.85 in the cummins.
Diesels definatly have a place in the under 8500 GVWR vehicle for me I would keep it much longer.
 

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Discussion Starter · #16 ·
Why should there be a premium for a diesel? Why are paying an extra $1000.00 for 5.3 l over 4.8l ?
I think they put a premium on because lemmings like we are will pay it. :chef:
 

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Diesel technology just keeps getting better and better. So I think we will see more vehicles with diesel engines as a option in the future. My next new truck will be a diesel for sure. I love my gas 6.0L, but performance you can get out of a diesel is much greater than a gas motor. The new Durmax LLY is a perfect exapmle of that. The diesel engine will become more popular I think as time goes by.... :D
 

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the really disappointing thing is that GM wouldnt even ened to develop a new engine....Isuzu has one sitting in their D-MAXX...
 

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Originally posted by desmo9@Feb 27 2004, 12:54 PM
Weight of a truck has almost no bearing on highway mpg, where the low-20s figure comes into play. Aerodynamics, rolling resistance, and gearing are about it.
You're kidding right? I hope so because weight has a HUGE effect on gas milage. What do you think effects rolling resistance (besides tires)?

Diesels cost more because the cylinder pressure is so much higher that premium materials / components are required. What I don't get is that if the OEs put as much $$ into developing SI engines such as 42 volt systems, electric water pumps, steering pumps, AC compressor, etc, pneumatically controlled valves, regenerative braking, the list goes on - the economy might be as good or better than diesels. Gain efficiency by increasing volumetric efficiency through turbocharging and reduce pumping loses.
 

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Does anyone know if a small deisel is ever being considered at GM? You would think that with Izusu under its arm, gm costomers like us would be flooded with alternative engine options. Ford was at one time considering a smaller diesel.
The inline 4 gas in the colorado should get excellent mileage, but I would buy one(deisel) if it was the right price and was of good quality.
..Then again, I was only 10 years old when GM had the diesel problems in the early 80s, not old enough to own or drive one of those vehicles. I hear about it though, My dad used to own a truck with a 350 diesel, aparently, it was not a very good engine. It might be difficult to get people like him away from his trusty gas powered trucks (he is considering a new GMC with a D-Max, though, but it is a little more power than he needs)

I think a v6, around 4.0-4.5 liters with all of technological innovations that the duramax enjoys could command at least $1500 for an option, depending on the price of the truck, perhaps up to $2500 if offered on a full size truck. Especially if gas prices get as high next summer, and next year as they say. Diesel is comparably cheap around here-around $1.60 for deisel at every Exxon On The Tun, $1.75 for regular-----It is not even close to July 4th yet! Americans love trucks and SUVs, it would not be hard to make them less expensive to run, considering the increase of fuel stations carrying deisel fuel.

If you would consider any small duramax for a gm truck or suv, please post your thoughts or suggestions, perhaps folks at GM (I doubt that they will read this) will take notice.
 
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