320 CDI. I6 v V6
"The V-6 can be produced on the same line as the V-8 and V-12 engines."
This is rubbish ! The V6 diesel is produced in a dedicated, newly renovated plant in Berlin. At each step in the production process, the engine is checked by electronic robots for any imperfections. Upon completion, every engine is bench tested. The V6 is a purpose built diesel, an entirely different casting from any other gas V engine in the Mercedes stable.
"The V-6 MB Bluetec has the turbo sitting in the valley of the V. The heat must be terrible."
Yes, for the endurance trials @ Laredo, Texas (April 2005), the heat was so bad that all three E320 CDI V6 cars managed to complete their mission of travelling 100,000 miles at full throttle, averaging 139 mph for 30 days non-stop (except for driver changes and resupply of fuel & oil ).
I never said that the new engine is not as good as the old but merely surmising the fact that MB is doing this for the sake of cost savings rather than the inherent superiority of the inline engine over the V.
For your info MB also carried out a very similar stunt in Texas or Florida in 2004 or 2005, running the straight 6 diesels for hours or days to "prove" these engines were reliable, for propaganda purposes. In those days alloy heads were a novelty.
There is also a video about its build @ www.worldcarfans/german cars.
After you have witnessed the unprecedented quality control checks throughout the entire process, you might better understand why this engine has been flawless so far. I have yet to read of any problems with the V6 engine.
There is no question in my mind about the past and present reliability of the I6. It has been and remains an outstanding power plant.
However, I do not accept the argument advanced by a few owners of the 320CDI that the primary reason for MB to replace this engine was to save production costs. MB cannot afford to risk the well earned reputation of its diesel engines in order to save a few euros per engine. It would not surprise me if the V6, a more sophistocated design, actually costs more than the I6 to produce.
IMO, the motivation to design and engineer a new V6 diesel was brought about by having to meet the much more stringent emission standards and by the desire to produce greater performance with less weight.
The other benefit of the V6, mentioned by several posters, is its compact size, allowing for it to be fitted in a greater range of models.
There is no question in my mind about the past and present reliability of the I6. It has been and remains an outstanding power plant.
The v6 was introduced for two reasons: space & cost. As someone previously mentioned, the engines can now be be produced alongside the v8 engines, which reduces MB's production costs significantly. It also allows for an easier fit into the countless different models that MB now offers, especially those with 4matic.
I am not saying that the new MB v6 turbodiesel is better or worse than the old inline-6...time will tell which one is better. But the inline-6 engine design is usually smoother & more durable than the v6 engine design.
There is a reason that most big-rigs use an inline-6 turbodiesel instead of v6 or v8.
I agree 100 % Most here think we are picking on the new V6, it is not that. We know all V6s are a compromise, plain and simple.
The Best of Mercedes & AMG
The new v6 diesel could very well cost more than the old inline engine per motor, but I can all-but-guarantee that the development costs of the v6 & v8 diesel engines combined is less than the previous inline-6 and previous v8 diesel engines combined.
[/QUOTE]
How is this relevant to the original post ?
It seems to me that no matter what the facts are with respect to the V6 diesel, many owners of the I6 are convinced of its superiority to the V6.
I have driven both the I6 and the V6; there is no doubt in my mind which vehicle offers a better overall combo of engine and chassis performance.
Despite the acknowledged improvements to the handling dynamics of the 2007 E 320 Bluetec, some I6 owners continue to believe that that 2005-2006 E320 CDI remains the superior package, based primarily on their opinion that an iron block is far superior to an alloy one.
I see no merit in trying to argue this issue any further with I6 owners on this forum.
For me at least, the opinions of Bluetec owners hold more validity, especially those who have owned or driven the previous CDI.
In the words of one owner, the E320 Bluetec is "more fun to drive than my 2006 Porscke 911".
Another owner stated, that on the highway, his Bluetec "accelerates like an M3".
What has become clear to me is that the owners of both the E320 CDI and the E320 Bluetec are equally passionate about their respective diesel charriots !
Isn't that something worth celebrating ?
Last edited by DerekACS; Jul 2, 2007 at 01:36 AM.
Though I still prefer the design of an inline-6, I am currently looking for a CA legal GL320 cdi with the v6 turbodiesel as I am a bit more comfortable with the new motor based on some of the testimony I've read on this board.
Back to the original question: Though I personally prefer inline engines over V engines, I might have to go with the new v6 model for one main reason: no SBC! We have not encountered any problems with our SBC yet in 55 k miles (knock on wood), but with all of the horror stories, I figure it's just a matter of time.
Isn't that something worth celebrating ?
However, as someone once said,"the proof is in the pudding". Try driving a V6 back to back with your I6 and your concerns about a balanced engine will be laid to rest.
In a quote from the MB E Class brochure on the Bluetec engine, "the uncanny smoothness of this engine can be attributed to the Lanchester balancer shaft and extensive damping. Extra smoothness is added by the standard 7G-Tronic automatic transmission."
Last edited by DerekACS; Jul 2, 2007 at 12:30 PM.
Another owner stated, that on the highway, his Bluetec "accelerates like an M3".
As for the I6 vs V6 debate, on paper the two are nearly identical in terms of performance, economy, and weight...so the V6 was obviously not designed to be an improvement in these areas. Therefore it is as mentioned by others here...production efficiency and compatibility...so it is cost as a bottom line. Not that there's anything wrong with that...if they can make a V6 diesel as smooth, durable, and efficient as an I6 while saving the company money overall...that's progress.
So, upon reading your sceptical remarks (perfectly understandable if you haven't driven a Bluetec), I decided to do a little research to see if my impressions of the Bluetec's passing prowess were in fact accurate.
Well, here's what I found @ Car & Driver magazine :
In their test of the 335i coupe (Nov.2006), they stated that the top gear acceleration 30-50mph was 6.5secs and from 50-70 mph, it was 6.0 secs.
Now here's what they found for the same test with the Bluetec (May 2007); top gear acceleration 30-50mph was 3.7 secs and from 50-70 mph, it was 4.7 secs.
Perhaps now you have a better understanding why the Porsche owner that I quoted was also impressed with the Bluetec's performance.
Take a look at 1/4 mile times and trap speeds...that's more telling of the cars' acceleration capabilities. The Bluetec and CDI are almost identical, and way, way behind the 335i and M3.
1/4 mile, CDI: 15.3 @ 91 MPH
1/4 mile, Bluetec: 15.1 @ 92 MPH
30-50 MPH, CDI: 3.5
50-70 MPH, CDI: 4.8
30-50 MPH, Bluetec: 3.7
50-70 MPH, Bluetec: 4.7
Edit: For the record, the M3 is mid-13s in the quarter at 108 MPH, with the 335i just a tick behind. Not even in the same ballpark.
Last edited by Alan Smithee; Jul 2, 2007 at 10:51 PM.
Of course, I accept your point about a manual top gear v's auto transmission, but the figures I presented are correct. Actually, I found the top gear (6MT) acceleration of my 335i to be very impressive, with 300 lb.ft of torque on tap @ 1400 rpm.
In any case, when comparing the passing performance of these two vehicles, it's worth noting that that although the Bluetec is 14.9% heavier than a 335i, the Bluetec has 33% more torque !
It's that huge torque advantage that impresssed me.
Of course, I accept your point about a manual top gear v's auto transmission, but the figures I presented are correct. Actually, I found the top gear (6MT) acceleration of my 335i to be very impressive, with 300 lb.ft of torque on tap @ 1400 rpm.
In any case, when comparing the passing performance of these two vehicles, it's worth noting that that although the Bluetec is 14.9% heavier than a 335i, the Bluetec has 33% more torque !
It's that huge torque advantage that impresssed me.
No one said the Bluetec is not a good engine. OK?

No one said the Bluetec is not a good engine. OK?
Honda admitted it. No more Accords. Civic size suits battery cars.
http://www.autobloggreen.com/2007/06...to-hit-52-mpg/
http://www.autobloggreen.com/2007/06...to-hit-52-mpg/
Is the US 2006 CDI the same as the 320CDI model sold/serviced in France or do they use the Bluetec version ?
Any guidance would be greatly appreciated, as the cost delta to purchase a CDI in France is significant.
Thanks for yor help
Is the US 2006 CDI the same as the 320CDI model sold/serviced in France or do they use the Bluetec version ?
Any guidance would be greatly appreciated, as the cost delta to purchase a CDI in France is significant.
Thanks for yor help
The term "bluetec" is meaningless in most respects, as all it describes is extra exhaust stuff on the V6.
Is the US 2006 CDI the same as the 320CDI model sold/serviced in France or do they use the Bluetec version ?
Any guidance would be greatly appreciated, as the cost delta to purchase a CDI in France is significant.
Thanks for yor help
After that, only the speedometer would need to be changed and the 210km/hr limiter removed, only the suspension is slightly softer, otherwise, it is the same.








