320 CDI. I6 v V6
I`m getting a diesel something next year. I love MB and I also love and own bmw. Hard decision to make, either of them are great.
Lane
Should i buy with the new V6 or the old I6?
Can anyone tell me the difference between these two engines: Which is quieter, which runs smoother, powerdelivery......
Is the I6 engine identical from the day w211 was lunched to the day it was replaced with the V6 engine?
V-6 sleeved gas engine conversion, all the "V6" flaws.
Inherently the I-6 is a better design.
Regards,
Lane
The I6 CDI was introduced in 1999.
The V6 is in NO WAY a gas engine conversion, not even close.
Neither is inherently a better design than the other unless your criteria is frontal crash safety.
The In-line 6 cylinder engine is a 3.2ltr engine, the V6 is a 3.0ltr engine. The newer engine is allegedly quieter and smoother, but that smoothness will be down to extra balancing. The newer engine provides better performance, but to gain that better performance the engine has to be 'driven'. If you want a smooth, comfortable drive then the older straight six is the way to go, but if your looking for more aggressive driving then the V6 is better.
At present in the performance stakes the 3ltr 535 diesel is far superior to the Mercedes, but it is less reliable and prone to all sorts of turbo problems. What's better? A 'V' engine or straight. The answer is the straight, BUT you run into all sorts of design problems. Why has Mercedes-Benz gone the V6 route? The answer is simple, Design problems. The straight six was just too long and would not fit into the ML, plus putting the 7 speed transmission added problems, new pedestrian legislation.
Did the in-line engine have any improvements during it's time in the 211? The quick answer is YES. Sorry to everyone that said NO. During it's last year of production Mercedes-Benz stated they would upgrade from being EU3 compliant, to EU4, the result being a more thirsty engine.
If the V6 technology was better, then you could bet your bottom £ that BMW would have also dumped the in-line technology and changed to the alleged, superior V6. They haven't, because it isn't, so are folks silly for saying the in-line is better? Horses for courses. If you want a newer car then you have no choice.
I chuckled at the reference to the World Records that were set in Texas. I will respectfully point out these were set using imported European fuel, and if these V6 powered vehicles had attempted the fête using US fuel, and an older in-line engine was also used, I suspect the results would have been interesting. As I stated earlier though, this new engine only out performs the older engine when driven hard. The World record was good proof of that, but I would be screaming about why they did not use publicly available fuel?
Regards
John
From Sunny Torquay
The Best of Mercedes & AMG
The In-line 6 cylinder engine is a 3.2ltr engine, the V6 is a 3.0ltr engine. The newer engine is allegedly quieter and smoother, but that smoothness will be down to extra balancing. The newer engine provides better performance, but to gain that better performance the engine has to be 'driven'. If you want a smooth, comfortable drive then the older straight six is the way to go, but if your looking for more aggressive driving then the V6 is better.
At present in the performance stakes the 3ltr 535 diesel is far superior to the Mercedes, but it is less reliable and prone to all sorts of turbo problems. What's better? A 'V' engine or straight. The answer is the straight, BUT you run into all sorts of design problems. Why has Mercedes-Benz gone the V6 route? The answer is simple, Design problems. The straight six was just too long and would not fit into the ML, plus putting the 7 speed transmission added problems, new pedestrian legislation.
Did the in-line engine have any improvements during it's time in the 211? The quick answer is YES. Sorry to everyone that said NO. During it's last year of production Mercedes-Benz stated they would upgrade from being EU3 compliant, to EU4, the result being a more thirsty engine.
If the V6 technology was better, then you could bet your bottom £ that BMW would have also dumped the in-line technology and changed to the alleged, superior V6. They haven't, because it isn't, so are folks silly for saying the in-line is better? Horses for courses. If you want a newer car then you have no choice.
I chuckled at the reference to the World Records that were set in Texas. I will respectfully point out these were set using imported European fuel, and if these V6 powered vehicles had attempted the fête using US fuel, and an older in-line engine was also used, I suspect the results would have been interesting. As I stated earlier though, this new engine only out performs the older engine when driven hard. The World record was good proof of that, but I would be screaming about why they did not use publicly available fuel?
Regards
John
From Sunny Torquay
Did you see any inline sixes in Formula 1 in the turbo era? In the beginning BMW used 4 inline and won but was soon overwhelmed by the V6s.
Fuel was mostly irrelevant, although Euro fuel surely had some relevance as the engine was introduced there first.
No reason to make excuses for the formerly pathetic USA fuel.

The In-line 6 cylinder engine is a 3.2ltr engine, the V6 is a 3.0ltr engine. The newer engine is allegedly quieter and smoother, but that smoothness will be down to extra balancing. The newer engine provides better performance, but to gain that better performance the engine has to be 'driven'. If you want a smooth, comfortable drive then the older straight six is the way to go, but if your looking for more aggressive driving then the V6 is better.
I have no strong preference on the I6 over the V6 as such but I do talk from experience, not having had both but having both engines, although on different car models.
The V6 also comes with the 7G-tronic tranny which has larger range of gear ratio but smaller gear steps (higher fuel economy and better acceleration). After the initial hic-ups being fixed, one might consider this an important decision factor too.
The straight six simply takes up far too much space for the cars Mercedes-Benz now produce.
Totally agree with Diesel Benz and the 7 speed box could only be fitted with the smaller engines (in length
)John the very curious
Last edited by glojo; Jun 29, 2007 at 12:27 PM.
The straight six simply takes up far too much space for the cars Mercedes-Benz now produce.
I'm afraid your deluding yourself if you think the fuel was not a MAJOR factor in the acheivement of these impressive records. Who would import European fuel if it was not an important item? I personally thought the V6 CDI was introduced in the US roundabout the same time as it was in Europe and would appreciate clarification of this statement?
John the very curious
However, you seem to have ignored the fact that the V6 was designed to run on low sulphur fuel. This type of diesel fuel that was prevalent in Europe was not available in the USA when the Laredo endurance test was carried out in April of 2005, hence the necessity to import the LSD.
If you were not impressed with the fact that three E Class sedans with V6 diesels were driven a distance of 100,000 miles for 30 days at full throttle ( average speed 139 mph) without any mechanical problems, then I guess you could possibly be described as a serious sceptic !
The V6 diesel entered production in the spring of 2005. However, it did not arrive in North America until October 2006 when ULSD became available throughout Canada and the US.
With respect to your comments about the V6 having to be "driven" in order to perform, I don't know if you have actually driven a V6 or not. But, from my experience driving both the I6 and the V6, there are some notable differences betwen the two engines and the two cars. With the V6, there is less turbo lag, it is smoother, quieter and more responsive. The 7spd transmission is also smoother and faster shifting than the previous 5 spd transmission. The newer chassis has faster and more direct steering and the suspension is slightly stiffer. In addition, with the V6 being shorter, lighter and sitting further aft in the engine bay than the I6, there is a better F/R weight distribution which improves handling.
Nevertheless, the I6 is a well proven engine with a solid reputation. Mercedes decision to go with a lighter, more compact V6 engine was most likely driven by the ever increasing demands for cleaner emissions both in Europe and North America. Had it been possible to engineer the I6 to meet the much more stringent emissions standards, it would most likely still be in production.
Cheers to you in sunny Torquay
If you were not impressed with the fact that three E Class sedans with V6 diesels were driven a distance of 100,000 miles for 30 days at full throttle ( average speed 139 mph) without any mechanical problems, then I guess you could possibly be described as a serious sceptic !
I fear you are misinterpreting my post. First off to answer the main thrust of this paragraph. I was mega impressed. However that was not why I was making the point.
I have dared to put my head above the parapet and suggested the fuel used in achieving this excellent result was imported from Europe and played a significant role? That was in response to:
IF the in-line engine AND the 7 speed gearbox could have been fitted into the full range of Mercedes-Benz does anyone believe the in-line engine would have been replaced? A worthless question because it could not
I am NOT criticising the new V6.
Regards
John from sunny Torquay
On the E-class we actually saw the new face-lift vehicle that was fitted with the V6 in the summer of 2006
The older in-line engine has in my opinion very slightly more torque and to attempt to explain this I will suggest that going up slight gradients the larger engine (in-line) will deal with this easier than the smaller V6?
Regards
John from sunny Torquay
As far as torque is concerned with the V6, it is rated @ 400 lb.ft compared to 368 lb.ft for the I6, an increase of 9 %. Maximum torque for the V6 is available @ 1600 rpm - 2700 rpm.
In highway driving, the V6 torque is astonishing. Let me make a comparison for you. Until very recently, I was driving a BMW 335i coupe, which has 300 lb.ft of torque. It's passing power is very impressive indeed and has been praised by numerous reviews. But let me say that the V6 Bluetec is even more impressive. I was really stunned by the explosive acceleration that this car has on the highway.
I do not know if you have had a similar opportunity to experience this for yourself, but I suspect that you too would be impressed.
I cannot comment about other parts of Europe, but are they talking about the E-class, or the C, which did have the V6 in 2005? This is a 211 forum and I have no knowledge of the C history.
Unfortunately I am bed-bound and rely on my wife for the input. We have owned our E-class for a number of years and were given a face-lift vehicle with the V6 as a courtesy car when ours was serviced. Wife has ONE style of driving and drove the same vehicles in the same area. South Devon and in particular Torquay are in an extremely hilly area, hence my observations. The new gearbox tends to offer a gear for all seasons and your 'stunning acceleration' comment made me smile. The V6 is slightly quicker than the in line engine, but 'stunning'? I have always stated the newer engine is quicker\faster, that is a given.
Regards
John
but are they talking about the E-class, or the C, which did have the V6 in 2005?
The new gearbox tends to offer a gear for all seasons and your 'stunning acceleration' comment made me smile. The V6 is slightly quicker than the in line engine, but 'stunning'? I have always stated the newer engine is quicker\faster, that is a given.
Regards
John
My comment about the acceleration was made in reference to this car's passing ability, not 0-100 km/h. I hope that some day you will be able to experience it for yourself.
If you are interested in other opinions on the Bluetec V6, may I suggest that you check out www.edmunds.com
click on to New Cars, then select MB E Class, then click on Consumer Reviews. There are more than 30 owner reviews of 2007 E Class, including at least 8 Bluetec owners. One of these owners says that his Bluetec is more fun to drive than his 2006 Porsche 911 !!
By the way, I do think you live in one of the most beautiful parts of England. South Devon really is stunning.
Next time we come over to my ancestral homeland, we will have to revisit your county and perhaps we could share a pint or two !
Cheers from Vancouver
I thought the updated E-class was first seen at New York and then subsequently put on sale?
I think we are misunderstanding my point about the V6, at no time have I said it is less powerful than the older engine, I am trying (and failing miserably) to say it needs a different driver input to get the most out of it. I think we are picking on the wording and extracting the wrong meaning? I have inserted bamboo shoots into my wife's finger nails to ensure I am not being told porkies. However I can fully understand her points and what she is saying.
I'm not sure of the complete range of 4Matic vehicles that are available on mainland Europe, but your right, the UK does not get any of the C, S, or E 4Matic vehicles. I would love to stamp my feet and throw a tantrum over this issue, BUT it is NOT Germany picking on little olde Great Britain, as far as I'm aware NO that drives on the correct
side of the road gets this option? This is a DaimlerChrysler decision and it appears they will not consider changing it? You state that some Europeans have had the V6CDI since 2005, for my information I would love to know wnat country got the facelift E-class in that year? I try my hardest to give either factual or personal information, but if the E-class was released with the V6 diesel prior to 2006, then I apologise, but I would like a link to any information please.
Vancouver...... It would appear we have more in common than just owning a Mercedes-Benz! I thought Vancouver and the state of British Columbia were amongst some of the most beautiful places I have ever had the priviledge of visiting, although in my hazy youth I can recall on a Sunday hitch hiking into America just to visit a pub!
Happy days and lots of happy memories. I enjoyed visiting the West coast of that huge continent.... Haight-Ashbury in the late 1960's
Enough, enough. Kind regards,
John
from a cold, wet, damp, misty Torquay
I fear you are misinterpreting my post. First off to answer the main thrust of this paragraph. I was mega impressed. However that was not why I was making the point.
I have dared to put my head above the parapet and suggested the fuel used in achieving this excellent result was imported from Europe and played a significant role? That was in response to:
I believe you have confirmed my point and I agree with your most informative statement regarding this issue.
On the E-class we actually saw the new face-lift vehicle that was fitted with the V6 in the summer of 2006
I fear my wording might be misunderstood? The older in-line engine has in my opinion very slightly more torque and to attempt to explain this I will suggest that going up slight gradients the larger engine (in-line) will deal with this easier than the smaller V6? The V6 has the benefit of a 7 speed gearbox, but that is diverting the discussion. The smaller engine requires more driver input to maintain the same momentum, hence my description of needing to be driven. I certainly do NOT mean the engine is under-powered, I am merely stating it needs more 'input'. I also agree with your other points about new gearbox, improvements etc.
IF the in-line engine AND the 7 speed gearbox could have been fitted into the full range of Mercedes-Benz does anyone believe the in-line engine would have been replaced? A worthless question because it could not
I am NOT criticising the new V6.
Regards
John from sunny Torquay
The V-6 can be produced on the same line as the V-8 and V-12 engines. They are modular like the Ford Triton engines.
Cummins still make the straight six diesel engines for Dodge trucks. They are easier to work on with intake on one side and turbo on the other side. The V-6 MB Bluetec has the turbo sitting in the valley of the V. The heat must be terrible.
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.
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.
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.
Blow some black smoke!!!
"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 ).






