Mercedes New Straight Sixes - Thoughts

[MarkII]

It's now common knowledge that Mercedes are planning to launch a new range of modular engines, including straight sixes (which is a nice return to form) and these will power the new E-Class and eventually the long awaited and heavily revised G-Class (big fan of the G but it's needed a major overhaul for a while) but I wonder whether these engine will find their way into the C-Class anytime soon.

The current C-Class has been crying out for better engine options and whilst everyone seems to be downsizing, there's nothing quite like a smooth six, so I really hope they offer the inline sixes for 2017MY!

My ideal spec for a great everyday car would be a C-Class estate, AMG line in Palladium Silver with a panoramic roof, 400hp 3Litre straight six (quad turbo - two mechanical, two electric), 9G Tronic auto-box, 4Matic driveline (plus an aftermarket Quaife ATB diff in the rear), and Air Body Control. Throw in a red leather interior with carbon trim, COMAND, Burmester stereo with Pink Floyd 'Shine on You Crazy Diamond' playing, set the nav for some remote part of Wales or the Scottish Highlands and just drive....

Thoughts?

 

[S205-FTW]

C43 AMG should be out in the summer and tick near enough all those boxes. It will be a V6 rather than straight 6.

 

[MancMike]

I'd much prefer a V6 over a I6, even if it needs a balance shaft...

I know there aren't many/any straight 8s around, but if given the option between a I8 and a V8, which would you choose?

 

[MarkII]

C43 AMG should be out in the summer and tick near enough all those boxes. It will be a V6 rather than straight 6.

I know and I would consider one (the C43 AMG certainly ticks all my other boxes) it's just that the introduction of this new modular engine line does make me wonder when the V6 will be pensioned off, especially if as reported, a quad turbo version of the I6 could easily make over 400hp (eclipsing the 362hp of the current car)….

I'd much prefer a V6 over a I6, even if it needs a balance shaft...

I know there aren't many/any straight 8s around, but if given the option between a I8 and a V8, which would you choose?

It's personal choice but I'd always go for an I6 over a V6, partly because I prefer the sound and torque delivery that an inline 6 configuration gives and possibly that I have fond memories of I6 engines in Alpina and BMW cars from my past.

No disrespect but the I8/V8 question is a bit of a moot point these days - now if you had asked me I6/V6 or V8 - I'd instinctively go for a V8 however, with the on-going pressure to down-size and minimise emissions, I wouldn't be surprised if the current AMG V8 doesn't give way to an inline 6 in time....and why not, an AMG GT which can trace its roots back to the original I6 equipped 300SL

 

[StuartK]

The engines available currently in the new C are poor. Who the hell wants a 4 pot in a merc is beyond me

 

[John]

I'd much prefer a V6 over a I6, even if it needs a balance shaft...

I know there aren't many/any straight 8s around, but if given the option between a I8 and a V8, which would you choose?

I do like V6 engines but I enjoyed the smooth sound of the I6 engines I had in the BMWs I owned which had them - so I would say they are on a par for me.

 

[Red C220]

I've not heard of these yet, is there a link to an article?

 

[theogeor]

Personally I like flat 6 . Saying that I see a gap in both the end as well in ghe c class in terms of oetrol engines. A 3l or even a 2.5 and above i6 will provide a more complete range

TG

 

[MarkII]

I've not heard of these yet, is there a link to an article?

There have been rumours about the new engine line since 2011 - which would make sense for roll-out in 2016/17

Merc to revive straight six, plus 4cyl and smaller V8s by CAR Magazine

And more recently: Looks Like Mercedes' Inline-Six Revival Will Come With Lots Of Turbos

The launch of the new E-class seems like the first model that will be offered with the new range of engines. If the previous speculation about the modular engine line-up is correct then it would make sense for the new 2.0L I4 diesel (which replaces the 2.1L unit) to be followed maybe next year(?) with a new 2.9L I6 (replacing the current V6).

 

[Red C220]

Well a modular system makes sense from a manufacturing perspective.

Am I right in thinking the straight 6 is the only naturally balanced engine and most other configurations require some form of balancing?

 

[Bellow]

Well a modular system makes sense from a manufacturing perspective.

More from a development perspective I think - in-cylinder air flow, combustion, etc. Develop one cylinder then duplicate.

Am I right in thinking the straight 6 is the only naturally balanced engine and most other configurations require some form of balancing?

It's all here.

AutoZine Technical School - Engine

V6s suffer from rocking couples (the end to end vibe), I6s perfectly balanced - primary and secondary. Eliminating a balance shaft (as an I6 can) reduces friction to the benefit of economy.

 

[Charles Morgan]

Excellent resource, thanks Bellow.

In the absence of a V12 my favourite engine configuration for refinement and performance is a straight six.

 

[Bellow]

Excellent resource, thanks Grober.

.

FTFY. Grober first posted it on your W114 thread!

 

[Charles Morgan]

Sorry Graeme, I can only plead the senior moment defence...

 

[Bellow]

Sorry Graeme, I can only plead the senior moment defence...

Possibly not.
Thinking about it, I think it was posted on BM's Pajero thread.

 

[Charles Morgan]

I read that too...

I think.

 

[grober]

From AUTO BILD
The technology of the new E-Class: The V6 is obsolete


Currently, Mercedes provides the luxury of three different cylinder spacings in their engines : 90, 94 and 106 millimeters. From 2016 unification is announced: 90 mm spacing and Cylinder capacity nearly 0.5 liters, = 60 percent common parts between diesel and petrol engines and between four and six cylinder. Effect: a cheaper production by 35 percent. The condition is that the V6 is replaced by a newly designed, exceptionally smooth straight-six. Specifically two: a diesel (OM 656, 2.9 liter displacement) and a petrol engine (M 256, 3.0 liters). The technical features of the petrol engine: in-engine measures to meet EU 6, double camshaft phasing "CAMTRONIC", turbocharger with variable vane geometry, electrically driven water pump.

but some interesting comments also on what Mercedes calls "the green washers" i.e. the in-line electric motor between engine and gear box in their hybrid models .

At Mercedes, although the current gearbox remains for the small four-cylinder in the program, most E-Class customers can turn In future to a nine-speed automatic transmission . Between the engine and gearbox rotate on request three different thickness "green washers", as Mercedes calls its hybrid components. The version with 40-horsepower electric motor is the mild hybrid package reserved (diesel and gasoline), the 80-hp electric motor is part of the four-cylinder plug-in hybrids. The 110 PS strong E-business is probably assigned only to the six-cylinder.