# what do you think of CRD diesel engine cars?



## picard (Jun 3, 2006)

What do you guys think of CRD diesel engine used my Jeep and Mercedes? Are they more durable than regular gas engine?

Does it still have the torque and power for the car for passing on Hway?


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## cobb (Jun 3, 2006)

CRD? I cant speak for that, but direct injection is way better than the old swirl ports.


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## RoninPimp (Jun 3, 2006)

CDR = Common Rail Direct injection if IRRC. The latest tech in diesels. Diesels are the future imo, especially curning bio diesel. I look foward to being able to buy a diesel Audi or Toyota in the near future.


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## BIGIRON (Jun 5, 2006)

I've owned a number of diesel vehicles - boats, trucks, cars, tractors. Currently own Ford, Kubota and MBZ diesels.

Historically, diesels have been desirable because of great low end torque, economy and durability (re-buildability). Hard haulin' trucks and high mileage travelling salesmen have been the primary benefactors of diesel advantages.

Modern gas engines and lubricants are improved to the point that the economy and durability difference is not that significant.

At the price differential of gasoline/diesel (diesel .20/30 cents gal more around here) and the initial cost premium of the diesel engine, the catch up may be several hundred thousand miles. A well manintained modern gas engine can be expected to perform well for 200k miles or more.

Most diesel engines require oil changes at less miles and use (usually a lot) more oil per change.

The torque differential remains, but do you really need 400 ftlbs to go to the grocery store. If you regularly tow a 6 horse trailer, then sure. The larger gas engines give up very little, if anything, in the performance department.

Diesels are relatively noisy (older ones are really noisy!) and smelly. Fuel is not at every station and costs more. You will get fuel on your hands (and feet where the fuel has been spilled) - it has an unplesant smell and does not just wipe off. If you've not had the diesel experience, it would be nice to rent or borrow one for a couple of days before purchasing.

Many, if not most, current diesel buyers would be better off, practically speaking, with gas engines.

The biodiesel, etc, "advantage" may or may not be real and lasting. I don't consider it. Whenever possible, I will never use anything but the best and freshest fuel I can find in my diesels. And I can't imagine putting any thing other than good, clean fuel in a new small, high performance diesel.

I'm certainly not anti diesel, just putting out a couple of real world things to think about. Were I buying a new vehicle, even a work or camper truck, I would probably buy gas.

I believe, and have posted several times, that there will be a real fuel crisis. Gas at and maybe exceeding $5 gal and sometimes not available. I think it's probable that diesel fuel will be more readily available than gas then (if it's not rationed to "critical" users - i.e. government, over the road truck, construction, etc.)

BTW - diesel fuel does not store well. Not good to lay in a long term supply.


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## chevrofreak (Jun 5, 2006)

Its really too bad diesels sound like a box of rocks rattling away under your hood, or they might have taken over already.


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## chevrofreak (Jun 5, 2006)

Oh, and every diesel I've seen has emitted that sexy cloud of black smoke upon starting or hard acceleration. I know that can be tuned out pretty easily, but that wont fix the cars that already exist.


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## BIGIRON (Jun 5, 2006)

On the other hand, countering (with a smile) Chevrofreaks comments -- modern auto diesels are generally very quiet -- you have to be standing within a few feet of my MBZ to know its a diesel. The Ford camper truck, on the other hand ----- I cringe when I start it early in the morning in a campground or here in the neighborhood. It's LOUD -- but quietens a lot when warmed up.

Modern diesels, properly tuned, just don't smoke. My MBZ (a turbo) after a lot of low speed operation, will emit black soot (not smoke) when it's kicked. That cleans out in a few seconds and then the exhaust is clean.

My Ford and Kubota don't smoke at all.


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## twentysixtwo (Jun 5, 2006)

CRD is the way to go. Much more durable than gasoline engines and with performance comparable to gas. If you don't look under the hood you wouldn't be able to tell the difference under most driving conditions.

For those who are unfamiliar, CRD (common rail diesel) is an industry term for what laypeople would call direct injection. It is typically combined with variable turbo boost which makes for a much more responsive engine than your old style diesels.


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## chevrofreak (Jun 5, 2006)

BIGIRON said:


> On the other hand, countering (with a smile) Chevrofreaks comments -- modern auto diesels are generally very quiet -- you have to be standing within a few feet of my MBZ to know its a diesel. The Ford camper truck, on the other hand ----- I cringe when I start it early in the morning in a campground or here in the neighborhood. It's LOUD -- but quietens a lot when warmed up.
> 
> Modern diesels, properly tuned, just don't smoke. My MBZ (a turbo) after a lot of low speed operation, will emit black soot (not smoke) when it's kicked. That cleans out in a few seconds and then the exhaust is clean.
> 
> My Ford and Kubota don't smoke at all.


 
Living in Montana I see a lot of diesel pickups, most of them smoke. I see delivery trucks and Dodge cummins diesel trucks clouding up the street all the time. Not all of them smoke like that though. I don't think I've seen a Chevrolet with a Duramax create much smoke. The new Banks diesel upgrade kits with computer modules supposedly nearly completely eliminate the smoking.

There aren't many diesel cars here, but the ones I do see are old Mercedes, or new VW's. I drove past a brand new Volkswagen TDI the other day that sound like it had a cement mixer full of rocks where the engine should be. Those little things sound so horrible that I don't think I could ever drive one, even if it does get 50mpg....

V8 diesels do sound quite nice though, especially with an open exhaust. I think the typical diesel engine sound starts to disappear with more pistons. The VW V10 diesel in the Touareg doesn't make much diesel sound at all. Those little 4 bangers however......


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## Diesel_Bomber (Jun 5, 2006)

Bring on the diesel revolution! Of course, I'm heavily biased. 


Seriously, I think a larger variety of smaller diesels will be for the better. I see a lot of people driving a full size diesel truck to the grocery store and to pick up the kids from school. Upon asking, I find that several bought theirs because they wanted a diesel, but the only cars available were small VW's, an expensive Mercedes, or full size trucks. They chose the truck. I'm sure a diesel Cherokee and Liberty will garner some of that market share, not that I think the Liberty is much bigger than a VW. Also, I'm sure there are lots of people who need a larger vehicle than a VW but can't afford a full size truck. When it comes down to it, people will buy what they want and manufacturers will build what the people want. Be it vehicles or flashlights.


Cheers. :buddies:

P.S. I love my loud, smelly Cummins. It didn't smoke when it was stock, but I can leave a nice cloud now.


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## blahblahblah (Jun 5, 2006)

I drive a Chevy 2500HD with a Duramax 6.6L Diesel. I know it's not a grocery-getter vehicle engine, but it does use common rail technology. The amazing thing about diesels that needs to be stressed is GREAT FUEL ECONOMY. My truck weighs in at 8500lbs on an average day and I get up to the low 20s MPG on the highway (bigger tires and about as aerodynamic as a brick). The 20 -30 cents per gallon difference we are paying at the pump is less than 10% over gas prices. A comparable vehicle to mine would be getting about 16 MPG at best on the hwy. I am getting a 25%+ increase in mileage for a 10% increase in fuel costs. 

Beyond economy, the power of a diesel is hard to beat (for trucks). I don't know if you need the power on an average SUV, but many have a heavy right foot. Diesels are very easy to upgrade for more power. It usually only involves plugging in a chip. For my truck... IIRC, Factory HP and torque numbers were 300/590. After adding a chip for $500, my power increased to 450/850. In a gasser, those power increases would be insanely expensive.

With regards to smoke... Smoke is a by product of excess fuel. New factory diesels do not produce the smoke of old diesel technology! If a factory diesel is producing smoke, there is something wrong with it! Adding power as stated above, can produce smoke however. Also, living in CA, the diesels are equiped with catylitic (sp?) converters.

With regards to sound... Yes diesels are noisy compared to gas. However, newer diesels are MUCH quieter than the old technology.

With regards to storing diesel... Diesel will grow bacteria or other biologicals over time. It is easily resolved w/ a fuel additive, similar to the one you put in your lawnmower over winter. This is NOT even necessary, if you go through a tank of diesel in your vehicle at least every few months.

With regards to durability... What do the big rigs run?

Marco


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## twentysixtwo (Jun 5, 2006)

Smoke *can* be the result of excess fuel, most common on startup when the engine is cold. However here in the states a lot of it has to do with Sulfur content. 

In Europe, Low sulfur content and particulate traps make Diesels as clean with regards to smoke as gas engines. Unfortunately you'll never get rid of that "Sour" smell, a result of NOx emissions.


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## lorenzolokibi (Jun 5, 2006)

In France, I think about 60-70 % of the private car market is running on gasoil, and maybe 2/3 got TDi/CRD engines. I think that only little city vehicule and very powerful sport cars are still running on leadless gas. The traditionnal drawbacks of the old gasoil engines disappeared (even my working truck is more discreet that my gas-powered Honda...). And I can run about 650 miles on about 21 gallon (80 liters). That's cool. And we _never got a trouble_ with the five engines of our fleet since five years.


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## Brock (Jun 5, 2006)

I have found the loudness of the engine depends on the fuel used. Sometimes I can hear the clank of the diesel sometimes I can't. If I add even 5% bio-diesel it gets quiet as can be. I can't image a VW being "loud". I often hear gassers that are louder then our VW, even a gasser with a good muffler.

Also diesels don't have mufflers per say and the engine actually gets more quiet under load, unlike a gasser. At cruising speed you hear no knock what so ever. The loudest knock is at idle under no load.

I also very rarely “smoke” the only way is to floor it on an on ramp in second, otherwise I never see any smoke, even on a clod morning.

Once you go diesel you will never go back. My wife even now wants us to get a Sprinter van because it is diesel.


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## db (Jun 5, 2006)

A friend of mine, who works for a diesel engine maker, told me a while back that they are programing/tuning some of the noise back into the engines. I thought that he said buyers didn't like their diesel trucks *not* sounding like a diesel. Not postive on that reason though, as it was awhile ago.


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## drizzle (Jun 6, 2006)

blahblahblah said:


> Diesels are very easy to upgrade for more power. It usually only involves plugging in a chip. For my truck... IIRC, Factory HP and torque numbers were 300/590. After adding a chip for $500, my power increased to 450/850. In a gasser, those power increases would be insanely expensive.


How can this be? I have a hard time believing that the manufacturer didn't try to tune it to the maximum power. What is the trade-off? Does this aftermarket chip bypass emissions standards?


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## Tooner (Jun 6, 2006)

drizzle said:


> How can this be? I have a hard time believing that the manufacturer didn't try to tune it to the maximum power. What is the trade-off? Does this aftermarket chip bypass emissions standards?


 
I think that yes, the emmisions are a problem with a chipped engine. The chip is basically adding more fuel. So if you lived in an area that required you to DEQ your diesel truck I would think you would at minimum have to set your chip to the stock position. Maybe even pull the chip to pass DEQ. (I don't know for sure as I live in an area where diesel trucks are DEQ exempt.) Most chips now days have a selector knob with different programs, that you can select on the fly. I have an older 3 way chip that has +50, +80, +120 horse settings. But it could be programmed to have a stock position in place of one of those settings. Many newer chips come with 6 different settings. So having a stock position is no big deal. I'm sure someone that has some experience with DEQ will chime in. 

The trade-off is you run the risk of bad things happening to the motor and the transmission. And that you could violate your warranty and thus have a situation where you are on the hook for repairs even though the chip may or may not be the culprit that caused the need for repair. Many people wait until the warranty has expired to chip it. The old saying that applies here is "You play, you pay."


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## twentysixtwo (Jun 6, 2006)

You can significantly increase power with a calibration change, though I have to admit I'm skeptical that you can get 50% without some other change (e.g. turbo modifications,etc)

A bigger downside than emissions is fuel economy. Typically engine durability isn't a big deal, particularly in diesels. I imagine people with chipped engines blow them more often, but that's due more to driving style than changing the calibration.

What always makes me laugh is when people say they have a chip that gives them more power AND better fuel economy. This is pretty much impossible with only a software change - I'd believe it if they said that they swapped trannies and went from a 4 speed to a 6 speed, but if all you are doing is changing the software, you're definitely going to be trading off.....


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## db (Jun 6, 2006)

I sent a link to this thread to a friend...

His reply:



> you got it right.
> 
> tell the other guy the way you get better MPG and more power is you stop spraying 1/3 of your fuel in to cool off the exhaust to meet emissions. The epa's limits are not inline with whats best for everyone. But right now you have to spray some fuel after the power ignition to get the gas temps down High gas temp causes more NOX and the EPA goes after Nox which is only one part of the emissions


 I think that the _"got it right"_ comment is in reference to the tuning of the noise back into the engines, posted previously.


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## PlayboyJoeShmoe (Jun 7, 2006)

I think I've crowed enough about the Cummins, but here goes...

My truck weighs 8,000 LBS give or take (depending on how many parts I have). I pretty regularly pull 5,500 LB trailer, sometimes pull 26ft Gooseneck Camping Trailer and OFTEN have from 1 to 6 55 Gallon drums in back.

Lifetime (that I've had the truck - about a year now) Avg. Mileage is about 19.5

I promise you a gasser doing the same stuff would be lucky to be at 15mpg.

If you "Leg" it, it goes remarkably well. But I drive primarily for mileage.

And it used to smoke when "legged" but the one varifiable property of using Acetone in my truck is that it DOES NOT smoke at WOT anymore.

I REALLY like my CRD Cummins!!!


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## scott.cr (Jun 7, 2006)

Tooner said:


> The chip is basically adding more fuel.



A lot of people don't understand the fundamentals of diesel throttling. A gasoline engine uses and air throttle and diesels use fuel supply as the throttle; the "throttle body" is always wide-open. This is why 18-wheelers use exhaust brakes; there is no natural engine braking effect as in a gasoline engine.

A diesel runs a very lean air/fuel ratio, and although more power is made when more fuel is added (ie. the chip as Tooner mentioned) exhaust gas temp (EGT) climbs accordingly.

Peak EGT is reached at stoichiometric air/fuel ratio, and as more fuel is added to a diesel it will approach stoichiometric = engine damage. (The damage can vary from a burned exhaust valve to turbine damage, piston damage, etc.)

Having said all that, a few months ago Autoweek did a fuel economy test comparing the VW diesel to some hybrid cars (among others), and the diesel VW blew them all away in the fuel economy department, achieving 52 mpg!! But it was also the slowest in the test, even slower than the Prius. I think its 0-60 time was in the high 10-second range.

The current crop of CRDs allows very tight control over emissions and noise because the CRD injector works similar to a gasoline injector: Peak fuel pressure is reached before the injector opens and delivers fuel. In the regular direct injection diesels fuel delivery ramps up, peaks, and ramps down like a sine wave... CRD would be more like a square wave.


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## twentysixtwo (Jun 7, 2006)

db

Emissions always trades off with Performance / economy, so if you basically don't care about polluting the air, then you can get improved Performance / economy.

Performance and economy then trade off with each other. This would mean that it IS possible to get an incremental improvement in both, though DEFINITELY NOT for the reason your friend mentions. Diesels run lean of stoich so spraying more fuel after ignition would RAISE combustion temps, not lower them. However,if you are talking about 50% increase in power then I'd have to assume that you're sacrificing economy as well. 

BTW, I spoke with some diesel calibrators and they thought the max you could get from dropping the emissions was like 20-30%. not 50%. The 30% was really for 2007 -2010 product when DPF becomes a requirement. 

BTW, if your chipping friend has probably toasted his cat.


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## Brock (Jun 7, 2006)

Yup to get a 50% increase on the VW's you have to chip and swap out the fuel injectors for larger ones. It is quite common to replace a .161 injector with a .205 or even a .220. Some claim the larger injectors can increase mileage that is if you can keep your foot out of the power since it can inject all the fuel at once and essentially advance your timing and supposedly has a better spray pattern.

For the record my lifetime is 53.59 mpg over 47584 miles, I am not chipped nor do I have larger injectors, stock so far, although I am thinking of swapping my 5th gear to what would be a 6th gear.

I have yet to have anyone follow me up an on ramp, more then enough power for any driving I do.


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## PlayboyJoeShmoe (Jun 7, 2006)

I could probably do 40-50% of what i do with a VW TDI. But I'll probably never get a chance to try it.

I'm glad the Ram does as good as it does! On the trip down to Houston I had 2x55gal and 1x30gal drums in the back. The Low Boy with 3xCages that hold coke machines and the trailer itself has a heavy frame and heavy wire mesh deck. I left Shepherd at 21.3 on the AVG. readout. I had to plunk around a bunch of surface streets and LOTS of stop and go. Last act was to load up the Skylark we brought back and get us back up to Shepherd. The final readout was 19.5.

That ain't too shabby! And I CERTAINLY couldn't have done today with anything less than the Ram!

I'll NEVER go back to gasser. NEVER!


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## Kristofg (Jun 8, 2006)

scott.cr said:


> there is no natural engine braking effect as in a gasoline engine.


There is engine braking in a diesel actually, but the problem is that diesel engines are only supposed to keep low rpms. So you have to get to the next gear when you reach 3000 rpm on most VWs. A higher gear means less friction being generated by the engine and the car increases speed downhill.


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## Brock (Jun 8, 2006)

Playboy, that reminds me of a guy on the TDI forums. He was asking about his mileage on a 1000 mile trip he took and complaining he only got 35 mpg on the whole trip and then at the end of his post he admitted he was towing some SUV the whole way  I am sure it was the best mileage his SUV ever got


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## PlayboyJoeShmoe (Jun 8, 2006)

Sounds like it WOULD make a difference!

Depending on the size of the TDI vehicle and the SUV towed, that's still pretty darn good mileage!


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## picard (Jun 10, 2006)

jeep will discontinue Jeep CRD model this year due to poor emision standard. Jeep grand cherokee will get new Mercedes diesel for 2007 which will meet new emision standard.


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