Ram1500 EcoDiesel V6 revealed!

[DeereMann]

I think you may be confusing chemical potential energy ( diesel fuel vs gasoline BTU's) with thermal efficiency of an engine. They are 2 different things. Both are very relevant but separate issues of science.
The Eco-boost deserves credit for bringing diesel like low rpm torque with the advantages of a gas design, such as simple emmisions, oil requirements, cold weather etc...
Ram deserves credit for bringing an affordable true diesel to a segment of people who might fancy the idea of having a true diesel with it's low rpm torque. This same group of buyers would not buy a diesel otherwise.

Not much unlike the recent popular explosion of subcompact diesel "tractor" sales to everyone with 1/4 acre grass to mow...

Thanks for comment, DarkBlack. It is true I mixed both subjects - but that was for simplicity's sake because both are relevant here.

There is no question that chemical potential energy of ASTM D975 No. 2 diesel fuel is higher than gasoline, though the difference has become narrower because of ULSD stripping some of the heavy fractions out.

It also is true the compression ignition engine in general has higher thermal efficiency than the spark ignition (otto cycle) engine. That gap has also been narrowed some, not due to turbocharging of SI engines, but due to some of the direct gasoline injection engines that have the ability to cycle between regular stoichiometric (rich burn) operation when loaded, and lean burn at low load. Of course, this requires all the fancy ECM electronics of the FAE diesel engines to do so.

The combination of these two means the diesel engine is still 'X' times more efficient - it burns less fuel per mile at the same loads & conditions.

The peak cylinder pressure of the diesel is almost always higher than that of gasoline. But - this too has narrowed as the FAE HPCR diesels, with piezoelectric fuel injectors, are able to inject up to 5 times a combustion cycled to reduce the peak pressure and 'flatten' the pressure/time curve. Since pressure correlates to temperature, and temperature correlates to NOx pollutant formation, this reduces the NOx formation (still need SCR catalyst, tho). AND - it also reduces the combustion 'rattle' noise.

Still, the BMEP & PCP is higher on diesels because you want the overall area under the pressure/time curve to be as large as possible.

Some of these diesels are over 3,000 psi now. Gasolines? not so much. What is the ecoboost? Most S.I. engines aren't over 1,000 psi.

 

[Industrial Toys]

I hang out with a bunch of country boys from time to time. Any worth their salt, MUST drive a diesel!

Increasingly, many of these guys around here sport those HUGE upswept Exhausts, one or two. One young kid, did the farmers hankie, coming out of the gas station, I just yelled "NICE". He got into a lifted Dodge with a single upswept pipe. That thing sounded like a jet fighter taxiing around. Very, very cool. I can see the appeal.

I always wanted a Diesel p/u truck. When I finally got one of those discounted GMC 08s, (so I got the Duramax and Allison for Free) it really wasn't a REAL Diesel in my mind anymore and despite the SLT package didn't even give me a place to put my sunglasses!


It annoys me to see these third world types driving all these wonderfull mid size, high ground clearance, presumeably Diesel p/u trucks. Usually a belt fed 50 cal or so bolted into the back. Not a bad option to have IMO.

Plus, I find that all that with all the extra weight my 08 Duramax is a REAL PIG in the snow. Almost useless! And all those gadgets only make things worse in adverse conditions!

HEY, can anyone PLEASE tell me what I am supposed to be able to attach to those front hooks? I got stuck last week in my laneway, had all kinds of straps and chains and NOTHING fit in those dam hooks!

 

[3930dave]

Some of these diesels are over 3,000 psi now. Gasolines? not so much. What is the ecoboost? Most S.I. engines aren't over 1,000 psi.

Thanks for the peek behind the curtain DeereMann. It helps simple folk like myself, who get confused when they start trying to sort out why burning more fuel is better for the environment..... :scratchchin:

Those numbers you refer to are _____________ pressures ? If that's rail pressure, they seem low.

Rgds, D.

 

[buickanddeere]

What is the talk about diesel thermal efficiency? A 400HP diesel making 50HP rolling down the highway. Has lower thermal efficiency than a 400HP DI gasser making 50HP rolling down the highway.
Rare is the diesel purchase that actually makes economic sense .Who can stand there with a straight face and say the diesel option cost plus the extra diesel service and higher fuel costs per gallon.
Since 2006 at the latest. With the price of diesel and a EPA emissions equipment burden on current highway diesels. The advantage diesel used to enjoy is long gone. 1989 Cummins turbo diesel with a standard transmission vs the 1989 gasoline lineup with automatics was 25 years ago.

 

[3930dave]

What is the talk about diesel thermal efficiency? A 400HP diesel making 50HP rolling down the highway. Has lower thermal efficiency than a 400HP DI gasser making 50HP rolling down the highway.
Rare is the diesel purchase that actually makes economic sense .Who can stand there with a straight face and say the diesel option cost plus the extra diesel service and higher fuel costs per gallon.
Since 2006 at the latest. With the price of diesel and a EPA emissions equipment burden on current highway diesels. The advantage diesel used to enjoy is long gone. 1989 Cummins turbo diesel with a standard transmission vs the 1989 gasoline lineup with automatics was 25 years ago.

Basic thermo laws - energy converted in an IC engine is proportional to compression ratio.....

The USA centric "problems" with diesel engines centre around Taxation, EPA psychosis and perpetual expansion, Oil company investments in Govt, and un-negotiated trade barriers; to name a few reasons..... none of which have much (more like anything) to do with efficient use of energy.

Also, if the IC engine had been invented 100 years later, the 2 Safety issues I highlighted below would have probably ensured that Gasoline would have been quickly litigated out of existence.

Rgds, D.

Diesel engine - Wikipedia, the free encyclopedia

The diesel engine has the highest thermal efficiency of any standard internal or external combustion engine due to its very high compression ratio.

Major advantages

Diesel engines have several advantages over other internal combustion engines:

They burn less fuel than a petrol engine performing the same work, due to the engine's higher temperature of combustion and greater expansion ratio.[1] Gasoline engines are typically 30% efficient while diesel engines can convert over 45% of the fuel energy into mechanical energy[32] (see Carnot cycle for further explanation).

They have no high voltage electrical ignition system, resulting in high reliability and easy adaptation to damp environments. The absence of coils, spark plug wires, etc., also eliminates a source of radio frequency emissions which can interfere with navigation and communication equipment, which is especially important in marine and aircraft applications.

The life of a diesel engine is generally about twice as long as that of a petrol engine[33][better source needed] due to the increased strength of parts used. Diesel fuel has better lubrication properties than petrol as well.

Diesel fuel is distilled directly from petroleum. Distillation yields some gasoline, but the yield would be inadequate without catalytic reforming, which is a more costly process.

Diesel fuel is considered safer than petrol in many applications. Although diesel fuel will burn in open air using a wick, it will not explode and does not release a large amount of flammable vapor. The low vapor pressure of diesel is especially advantageous in marine applications, where the accumulation of explosive fuel-air mixtures is a particular hazard. For the same reason, diesel engines are immune to vapor lock.

For any given partial load the fuel efficiency (mass burned per energy produced) of a diesel engine remains nearly constant, as opposed to petrol and turbine engines which use proportionally more fuel with partial power outputs.[34][35][36][37]

They generate less waste heat in cooling and exhaust.[1]

Diesel engines can accept super- or turbo-charging pressure without any natural limit, constrained only by the strength of engine components. This is unlike petrol engines, which inevitably suffer detonation at higher pressure.

The carbon monoxide content of the exhaust is minimal, therefore diesel engines are used in underground mines.[38]

Biodiesel is an easily synthesized, non-petroleum-based fuel (through transesterification) which can run directly in many diesel engines, while gasoline engines either need adaptation to run synthetic fuels or else use them as an additive to gasoline (e.g., ethanol added to gasohol).

 

[Industrial Toys]

Buick .I just had my first brake job and not a complete one at that on my 08 Duramax. NOT a pretty bill! And I just went in to get my brakes "serviced".

One of the only consolations, is that my gently used 08, has a remarkably high resale value, I am told.

As far as the list of benefits of a Diesel, isn't this somewhat outdated? "High Voltage" ignition systems are hardly a model T coil anymore and even Diesel fuel itself has changed!

 

[timswi]

The CO2 thing is why you almost never (at least I never have) hear of someone doing themselves in with a diesel running in the garage...Would think the eye burning and smell would chase you out regardless of ones intentions. I know my diesel stunk up my garage fast, and I ad no alternative intentions...I opened the door and got out...Gas engines, different story.

 

[handirifle]

Interesting debate going on here. I know in some states the difference is larger, but here (CA), today the average gas price where I live was $3.65 a gallon for 87 octane. Average for diesel was $4.20 a gallon. Now I won't bring into account in my equation what the ACTUAL mileage returned by the long road test with the new eco diesel (31+) in the article in Diesel Now, magazine, but what I have seen regularly is 19 mpg. My 2006 Tundra 4x4 just gave me my hwy average of 15.1 mpg. Now mine is a 5,000 lb truck with a tow capacity of 7600 and for comparison the 2006 Duramax trucks are about 8,000lbs with a tow rating over twice mine. They regularly return anywhere from 18-22 depending on the gearing and driver.

So taking my 15.1 at 3.65 a gallon, vs a 19 mpg 3/4 ton diesel and the numbers are as such. Take a 1,000 mile sample of driving and getting my (normal by the way) 15.1 and that equals 66.22 gallons and at avg price of 3.65 = $241.72. For the same 1,000 mile run with a 3/4 ton diesel getting 19 mpg and $4.20 a gallon is 52.63 gallons used at a cost of $221.05.

This is a very straight forward cost comparison and does not factor higher purchase price, but considering I am NOT talking about the new dodge diesel, longevity has been proven, so that must be factored in to MY equation. My 2005 Honda Accord v6 gets 30 mpg on the highway, and if I were in the market for a 1/2t, and had the money, I would probably buy the new eco diesel. The towing tests in a 250 mile trip, towing 7000lbs returned about 19.5 mpg. That is 4 mpg higher than I get empty with almost identically equipped truck. Both are double cab, 4x4, and 6.5ft bed. The Dodge is probably heavier than mine too. The particular test truck had 3.55 gears and was rated for 6700 lb towing, but the trailer weighed 7,020, typical of what probably will occur when regular folks driver them. The same truck with 3.90 gears is rated for 8400lb and would probably return slightly lower mpg numbers, but not significant, in my opinion.

Keep in mind, that diesels are famous for having mpg improve after 100,000 miles. Personally I do not understand the thermal equations nor do I care. I care about pulling power, hauling abilities, and mpg, and long life. This will be my 7th year of owning my Tundra and it has a flawless record for reliability, and it pulls my 5th wheel acceptably, most of the time, but I get about 9 mpg when towing, compared to 19? The choice, for me, would be easy.

As some of you know, from my other threads, I am seriously considering swapping to a 3/4t diesel, but mainly for pulling power and upwards ability, pulling wise, for the future. I will tow with my Tundra for now with an open eye for a good deal on a Duramax. Keep in mind also that the more folks buy the diesels, the more likely they are to become more cost competitive with gassers. Our EPA is as responsible or more so, than anyone in leading us AWAY from diesels. I say bravo to the diesel industry for proving they are wrong.

Having said all that, let me state that for MANY years, I was NOT a fan of diesels, for many reasons, but I am now a convert. Someday!

 

[jejeosborne]

The flat part of the curve is ~420 ft.lbs.

I find the torque curves to be quite similar. Converting the claimed ecoboost 90 percent of 420 pound lb-ft (378 lb-ft) to Nm, I get 512 Nm. Ecoboost makes at least 512 Nm between 1700-5000 rpms. Like you say the diesel might start slightly sooner in the rpm range but peters out much quicker. Having good torque at the higher rpm ranges gives the ecoboost the larger HP peak. This is evident in the 0-60 times being posted.

Give me a pickup truck with the Ford ecoboost engine, Ram torque flight 8-speed, Ram coil spring suspension, and Ford payload. May I add the Toyota reclining rear seat and power rear window. Maybe the GM fellows can add something I forgot.

 

[fordmantpw]

Maybe the GM fellows can add something I forgot.

Heated tailgate? :laughing:

Seriously, though, what has GM been 'first' with in trucks lately? I would like to have the Ram Box feature on my next truck as well.