New Mercedes-Benz 4.7 Twin-Turbo V8 and New 3.5 V6

[south]

All of these criticisms of M-B's new engines may be ignoring a few crucial considerations: BMW and Audi (my presonal favorite) rely on turbo- and supercharging, respectively, to boost their 3.0 liter engines to the 300 HP mark. Lexus and Infiniti have high-compression engines of 11.8:1 and 11.0:1, respectively, to put their V-6s over the 300HP threshold. Along with other gains in efficiency, M-B sets its new 3.5 liter V-6 at 10.5:1 which makes for a less stressed engine which will hold up better over the long term. At that compression ratio, it could conceiveably be tuned to handle 89 or even 87 octane gas. (Alright, that last part is a pipe dream.) Very likely, the engine is also lighter, which will also help its performance. It appears to me that the boys and girls at Stuttgart have built an engine that makes more power on less with less complexity. How is this a problem?

I know this isn't your comment, so I hope you won't resent the following.

First of all, the compression ratio is wrong. Actually, the new V6 runs at a CR of 12.2:1 and thus higher than the others. On top of that, the V6 uses a stratified fuel injection. Without any doubt, this engine is a masterpiece of technical achievement, but Merc used a technology that doesn't necessarily make for better longevity. Other manufacturers, e.g. BMW, had quite some problems with their stratified DI engines in the beginning.


Best regards,
south

 

[Merc1]

Uh oh..........the compression ration is really that high?


M

 

[cawimmer430]

I'm sorry Chris but you're making excuses for Mercedes. The bottom line is that the E350 and C350 are outperformed by nearly every other car in their classes. No matter who hangs out where or who is passionate about what, 268hp just doesn't cut it anymore. People who hang out in forums are buyers also, again I quote buyers on MBWorld with W211 E350's who didn't buy a W212 E350 because they wanted more power, some of them switched to BMW others just kept their W211 E350s.

I don't feel that I am making excuses. I am convinced that many people don't feel that power is everything. Sure, there are people for whom the horsepower output is important, even though they'll never even use 80% of it. Then there are people for whom the principal just matters that the power is up to the ratings of the competition. Lastly, we have those for whom 268-hp is adequate and almost irrelevant.

The E350 can't hang with the 535i, the XF (which has a 300hp V8), or A6 3.0T, Car and Driver proved that when the new E came out and got beat by all those cars.

It can't hang with them from 0-60, but it's also not far behind. It will be last place in a drag race, but it won't exactly be left behind.

Furthermore, this type of driving and racing is something nobody will do in an E350, even with 306-hp. Only boy racers or performance freaks might try this, but then again the E-Class is the wrong car for such a task. Get an E63 AMG. Period.

Acura and GM/Cadillac just don't build as efficient drivetrains as the Germans do. Acura's 5-speed automatic is one of the oldest designs on the market as is the car. The CTS just doesn't put its 306hp down as well as the 268hp Benz does. I've driven the C350 many times now and its pretty fast so yes in reality for most people that is enough, but what I'm saying is that:

1. For buyers who want more Mercedes is lacking. Such buyers do exists. Clearly.
2. Mercedes-Benz shouldn't be this far behind in engine development or in the V6 class. Their V8s aren't.

You and I wouldn't cut Mercedes any slack for such a glaring lack of safety engineering would we? Of course not, we expect them to be on the leading edge of the field.

I agree.

But, from my perspective, and those of many others, the 268-hp is adequate. That's all I am saying. It's not slow or underpowered by any means - and if we're realistic it's more than anyone would ever need in real world driving.

I have zero problems if the E350 gets beaten in a drag race with a 535i or M37. The E350 is a cruiser, not a sports sedan. 306-hp under the hood will make it up to par with the competition, but will it drive or handle better? Hardly.

 

[martinbo]

Uh oh..........the compression ration is really that high?


M

It's direct injection stratified fuel injection - its whole raison d'etre is to enable higher compression ratios (equals more efficient combustion).

Barring Chris, am I the only one here it seems that thinks that:
- the new 3.5 litre V6's specific outputs are on-par-for-class
- a powerful yet efficient, naturally aspirated engine is a perfect powerplant in a mid-range, gentlemanly, E-Class with an excellent 7 speed gearbox

Remember, I said years ago - BMW were at a dead end with the 3.0 litre M54 and N52. Whilst they may have increased specific power output by incremental figures - achieving much more than the benchmark 100 Nm per litre was always a tough ask without either increasing displacement (which wasn't an option with the straight six) or introducing forced induction (which is what duly happened). In this sense, Mercedes Benz were actually ahead of the game with a more ubiquitously applicable 3.5 litre V6 and now they've made an even better one. Adding a turbo here or a supercharger there is child's play if it's needed as the next move.

 

[FC123]

It's direct injection stratified fuel injection - its whole raison d'etre is to enable higher compression ratios (equals more efficient combustion).

Barring Chris, am I the only one here it seems that thinks that:
- the new 3.5 litre V6's specific outputs are on-par-for-class
- a powerful yet efficient, naturally aspirated engine is a perfect powerplant in a mid-range, gentlemanly, E-Class with an excellent 7 speed gearbox

Remember, I said years ago - BMW were at a dead end with the 3.0 litre M54 and N52. Whilst they may have increased specific power output by incremental figures - achieving much more than the benchmark 100 Nm per litre was always a tough ask without either increasing displacement (which wasn't an option with the straight six) or introducing forced induction (which is what duly happened). In this sense, Mercedes Benz were actually ahead of the game with a more ubiquitously applicable 3.5 litre V6 and now they've made an even better one. Adding a turbo here or a supercharger there is child's play if it's needed as the next move.

No, I agree completely as well.

I see it thusly, Mercedes decides to introduce a new V6, as such it should better the competition quite a bit, either in a) power, b) fuel efficiency, c) a combination of both.

They clearly put the emphasis on b), while still matching the competition on horsepower. And to support Chris, we're talking about an engine, that sits middle of the line up producing more torque than an E46 M3 and just 37 horsepower less, not so long ago a S500 would put out 306 hp.

Should BMW decide to up the power on their new twin scroll 35i, this engine will be easily scaleable even without adding forced induction. FI would easily take it up to +400, should that be the brief.

 

[south]

Adding a turbo here or a supercharger there is child's play if it's needed as the next move.

May I add that it's not child's play when DI stratified fuel injection is involved. Correct me if I'm wrong, but I don't know of any engine out having both.


Best regards,
south

 

[Leech]

well I'm not shure but I think VW 2.0 TFSI in GTI is FI + DI oO

 

[martinbo]

? I'm confused south, are we missing each other somewhere in the terminology?

Direct Injection by its very nature delivers a stratified charge spray of fuel directly on to the piston top. So, many engines now combine either supercharging and turbocharging with DI: N55, S4 V8 FSI supercharged and so on...

 

[south]

? I'm confused south, are we missing each other somewhere in the terminology?

Direct Injection by its very nature delivers a stratified charge spray of fuel directly on to the piston top. So, many engines now combine either supercharging and turbocharging with DI: N55, S4 V8 FSI supercharged and so on...

Probably! I thought that stratified automatically means a spray-form DI. So to make my point clear, this new engine does have a spray-form DI which enables a lean injection at part throttle and at medium revvs. Neither the N55 nor the N54 nor the S4 V8 FSI have a lean mode, they always operate in homogeneous mode.


Best regards,
south

 

[martinbo]

^ Ok, I see where you're coming from - you are technically more correct. As I understand, though, the very nature of the finely atomised fuel spray (in a conical shape) that most DI engines create gives most of these modern DI powerplants the ability to run in a leaner mode.

 

[Tarek]

Entertaining and educating.

 

[cawimmer430]

I know people expect horsepower ratings to grow with the next generation, but let's go back to the year 1997 when the new Mercedes W220 S-Class debuted. Specifically, let's examine two models: the S500 and the S600.

Both these cars came with a 306-horsepower V8 and a 367-horsepower V12 respectively.

Odd.

The W140 S-Class (the ancestor of the W220) S500 and S600 had 326-horsepower and 394-horsepower respectively. That's more horsepower than the successor models.

Why did Mercedes do this?

Easy. Because pressure from environmental groups and from within Germany slammed the W140 S-Class for its size and thirst. The W140 was never as warmly received here as it was in America, where at that point literally nobody cared about the environment or fuel economy.

When it was time for the W220. Mercedes bowed down to environmental pressures and gave us the 306-hp S500 and 367-hp S600. And these cars outperformed their respective W140 brethren while getting much better gas mileage to. The secret to their success were improved transmission engineering, less weight and engine characteristics (torque band etc.).

So. Would you rather have a more powerful, yet slower and thirstier W140 S500 or a weaker, yet faster and more efficient W220 S500?


In a way, history is repeating itself - right now. Case point this new V6 from Mercedes. We know it makes 306-horsepower, which isn't "impressive" in the sense that four years ago rivals were offering this much power. But - what is impressive are the low emissions, which indicate a low fuel consumption. Furthermore, as the W220 S500/S600 have demonstrated over their W140 S500/S600 stablemates, better results can be achieved with less power. It wouldn't surprise me if (and I hope it does) if this engine in the "new E350" offers class-leading or at least highly competitive results in performance and economy.

 

[Merc1]

I don't feel that I am making excuses. I am convinced that many people don't feel that power is everything. Sure, there are people for whom the horsepower output is important, even though they'll never even use 80% of it. Then there are people for whom the principal just matters that the power is up to the ratings of the competition. Lastly, we have those for whom 268-hp is adequate and almost irrelevant.

True for some 268hp is good, but for some it isn't and the the people that aren't satisfied with 268hp aren't just pretenders they're actual W211 owners. That is all I'm trying to get you to see, that they aren't people who "wouldn't buy anyway" as you put it. They're real buyers.

It can't hang with them from 0-60, but it's also not far behind. It will be last place in a drag race, but it won't exactly be left behind.

Come on Chris, if the car can't hang then it gets left behind...lol. Thats what not being able to keep up means. The E350 gets smoked. The C350 Sport (which is not a luxury cruiser) gets it lug nuts handed to it by the 335i, G37S and Audi S4. Take out the S4 if you like, but the G37 and 335i are still there.

Furthermore, this type of driving and racing is something nobody will do in an E350, even with 306-hp. Only boy racers or performance freaks might try this, but then again the E-Class is the wrong car for such a task. Get an E63 AMG. Period.

It isn't about drag racing, its about being at least competitive with the class. Again, Chris the proof is clear...normal W211 E350 owners on MBWorld wanted more power before they upgraded, these are not performance freaks or boy racers Chris. You trying to blanket anyone that wants more power as being some type of boy racer or performance freak simply isn't accurate. They already won the W211 E350s and they wanted an upgrade. If they were so performance bent wouldn't they have a E550 or E63 already?

But, from my perspective, and those of many others, the 268-hp is adequate. That's all I am saying. It's not slow or underpowered by any means - and if we're realistic it's more than anyone would ever need in real world driving.

Point is though, it simply doesn't suite everyone. Clearly it doesn't and as I said above these aren't drag racers, these are existing W211 E350 owners. Your perspective isn't quite fitting in with a good number of U.S. E-Class buyers. Sure the majority is happy with 268hp, as sales prove, but a good deal aren't....that is all I'm saying and they aren't drag racers.

I have zero problems if the E350 gets beaten in a drag race with a 535i or M37. The E350 is a cruiser, not a sports sedan. 306-hp under the hood will make it up to par with the competition, but will it drive or handle better? Hardly.

Handle better, no. Drive better, yes. More power always adds to the driving experience.


M

 

[FC123]

I know people expect horsepower ratings to grow with the next generation, but let's go back to the year 1997 when the new Mercedes W220 S-Class debuted. Specifically, let's examine two models: the S500 and the S600.

Both these cars came with a 306-horsepower V8 and a 367-horsepower V12 respectively.

Odd.

The W140 S-Class (the ancestor of the W220) S500 and S600 had 326-horsepower and 394-horsepower respectively. That's more horsepower than the successor models.

Why did Mercedes do this?

Easy. Because pressure from environmental groups and from within Germany slammed the W140 S-Class for its size and thirst. The W140 was never as warmly received here as it was in America, where at that point literally nobody cared about the environment or fuel economy.

When it was time for the W220. Mercedes bowed down to environmental pressures and gave us the 306-hp S500 and 367-hp S600. And these cars outperformed their respective W140 brethren while getting much better gas mileage to. The secret to their success were improved transmission engineering, less weight and engine characteristics (torque band etc.).

So. Would you rather have a more powerful, yet slower and thirstier W140 S500 or a weaker, yet faster and more efficient W220 S500?


In a way, history is repeating itself - right now. Case point this new V6 from Mercedes. We know it makes 306-horsepower, which isn't "impressive" in the sense that four years ago rivals were offering this much power. But - what is impressive are the low emissions, which indicate a low fuel consumption. Furthermore, as the W220 S500/S600 have demonstrated over their W140 S500/S600 stablemates, better results can be achieved with less power. It wouldn't surprise me if (and I hope it does) if this engine in the "new E350" offers class-leading or at least highly competitive results in performance and economy.

The W140 S500 - W220 S500 change was a strange one, didn't the new car feature a 3v SOHC engine, whereas the old one was a 4v DOCH?

 

[Merc1]

Yep they went from DOHC to SOHC and 3- valves per cylinder. The W220 S500 though was a lighter car and so poorly built compared to the W140 S500.


M

 

[south]

^ Ok, I see where you're coming from - you are technically more correct. As I understand, though, the very nature of the finely atomised fuel spray (in a conical shape) that most DI engines create gives most of these modern DI powerplants the ability to run in a leaner mode.

I can only speak for the BMW engines with certainty. The N53 engines run in lean mode due to their spray-form DI system, but they're naturally aspirated. Both N54 and N55, despite their high pressure DI, run in homogeneous mode all the time. But who am I to disagree with you on engine tech.


Best regards,
south

 

[cawimmer430]

The W140 S500 - W220 S500 change was a strange one, didn't the new car feature a 3v SOHC engine, whereas the old one was a 4v DOCH?

Yes.

The 3-valve setup allowed the catalytic converter to reach its most efficient operating temperature 15 seconds earlier than the 4-valve design. Apparently MB though it was worth it.

I've never had anything against the 3-valve design from Mercedes. People seem to hate them for stupid reasons ("4-valves are better than 3-valves, duh!").

 

[Wunderkind]

Yes.

The 3-valve setup allowed the catalytic converter to reach its most efficient operating temperature 15 seconds earlier than the 4-valve design. Apparently MB though it was worth it.

I've never had anything against the 3-valve design from Mercedes. People seem to hate them for stupid reasons ("4-valves are better than 3-valves, duh!").

The three-valve set-up did indeed deliver much better start-up emissions than a comparable 4-valve set-up at the time. The reason being that the exhaust gases retained more heat through a single valve outlet and manifold and was able to heat up the catalytic converters faster.

But in terms of performance, the three-valve set-up was also less efficient (because of the big exhaust valve) and more coarse (especially at the top-end). The engine was never well-loved because of the coarse noise it made and it was not as rev-happy as similar BMW engines.

 

[Mr. Mercedes]

The three-valve set-up did indeed deliver much better start-up emissions than a comparable 4-valve set-up at the time. The reason being that the exhaust gases retained more heat through a single valve outlet and manifold and was able to heat up the catalytic converters faster.

But in terms of performance, the three-valve set-up was also less efficient (because of the big exhaust valve) and more coarse (especially at the top-end). The engine was never well-loved because of the coarse noise it made and it was not as rev-happy as similar BMW engines.

3 valve would have also been a cheaper desing no? Part of MB's cost cutting regime at the time?

 

[martinbo]

I can only speak for the BMW engines with certainty. The N53 engines run in lean mode due to their spray-form DI system, but they're naturally aspirated. Both N54 and N55, despite their high pressure DI, run in homogeneous mode all the time.

Thanks south, I didn't know that specifically.

But who am I to disagree with you on engine tech.

Nonsense. I've always said that I know only 10% of 10% of what there is to know about automobilia. I think your technical knowledge - especially BMW - is excellent and I learn a lot from you. I need to go and research the concept of: does the word stratified exclusively mean lean-burn or does the finely atomised spray qualify as "stratified". I don't know...

The three-valve set-up did indeed deliver much better start-up emissions than a comparable 4-valve set-up at the time. The reason being that the exhaust gases retained more heat through a single valve outlet and manifold and was able to heat up the catalytic converters faster.

But in terms of performance, the three-valve set-up was also less efficient (because of the big exhaust valve) and more coarse (especially at the top-end). The engine was never well-loved because of the coarse noise it made and it was not as rev-happy as similar BMW engines.

Hey Merc engine affionados - didn't the move from 24V DOHC valvetrain coincide with the change from inline six cylinder engines to the V6 layout? This ushered in the M112 range of engines replacing the inline six M104 as far as I remember. Also, the M112 range introduced dual spark plugs to achieve more even ignition across the cylinder.