Mercedez Benz News Mercedes-AMG Debuts Most Powerful Production 4-cylinder

[Drew Dowdell]

Mercedes-AMG has unvieled their newest and most powerful 4-cylinder engine. Clocking in at 416 horsepower and 369 lb-ft of torque for the S version, it is the most powerful 4-cylinder engine currently in production.  There is also a "base" model of this engine that produces 382 HP and 354 lb-ft of torque.  Peak torque for the S Model is available from 5000 - 5250 rpm while the base version's torque peak comes in at 4,750 rpm and continues to 5,000 rpm. Mercedes says that putting the torque peak higher in the RPM band makes the engine more free revving. Maximum engine speed for both versions is 7,200 rpm. 

The engine, while still transverse, is rotated 180 degrees to put the turbo in the back up against the firewall and the intake system is positioned up front to make for a lower design with fewer air restrictions.  The turbo itself is a twin-scroll unit and has roller bearings to reduce friction and quicken turbo response.  The engines are hand built by a single craftsman in Affalterbach Germany.  

No word yet on which vehicles these engines will go in, but its a safe bet to look for them to show up in the Mercedes A-Class, CLA-Class, and probably the GLB-Class.

Technical data at a glance

	Mercedes-AMG M 139 2.0 liter turbocharged four-cylinder engine
Displacement	1991 cc
Bore x stroke	83.0 x 92.0 mm
Output	416 hp at 6750 rpm (S-model)  382 hp at 6500 rpm (base version)
Peak torque	369 lb-ft at 5000-5250 rpm  (S-model) 354 lb-ft at 4750-5000 rpm (base version)
Max. engine speed	7200 rpm
Compression ratio	9.0:1
Turbocharging	One twinscroll turbocharger with roller-bearing compressor and turbine wheels
Max. charge pressure	2.1 bar (S-model) 1.9 bar (base version)
Mixture formation	Combined direct and manifold injection. 1.) Third-generation multiple direct injection. Fast and precise piezo injectors spray the fuel into the combustion chambers at high pressure  2.) Additional intake manifold injection with solenoid valves
Cylinder head	Two overhead camshafts, 16 valves, adjustable intake and exhaust camshafts, CAMTRONIC valve timing  adjustment for the exhaust camshaft
Max. air mass throughput	2,645 lb/h (S-model) 2,425 lb/h (base version)
Engine weight (wet)	353.8 lbs

 

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[ccap41]

7200rpm is pretty high these days for a turbo engine. It's probably a hoot to drive. 

[surreal1272]

Give credit where credit is due. That’s a lot juice for such a small motor. 

Edited June 7, 2019 by surreal1272

[Drew Dowdell]

I wonder if they'll make a longitudinal version. 

[daves87rs]

?

 

Want to drive!!!

[G. David Felt]

29 minutes ago, surreal1272 said:

Give credit where credit is due. That’s a lot juice for such a small motor. 

Yes allot of Juice, but pathetic still.

Still not sold on these overhead cam and in this case dual with high horsepower and weak torque.

Guess Germans like Italian love their High revving noise over actual grunt of moving.

Interesting note is that the Quad 4 always had more torque than HP without a turbo and still passed emissions.

Anyone that drove a Quad 4 could feel the grunt of movement in your gut without having to race the sewing machine engine.

[Drew Dowdell]

The torque doesn't sound weak, but it is pretty high up in the power band.   It is more usable when it hits low in the RPM range. 

[riviera74]

Why such low (peak) torque compared to peak horsepower?   This is the opposite of what any engine should be.  It's too bad other automakers' 4cyl engines have the same set of characteristics.  Too bad GM will not build a (non-truck) version of the 3800/3900 to replace the 3.6 V6.  Horsepower is great but torque is actually required.

[surreal1272]

1 hour ago, dfelt said:

Yes allot of Juice, but pathetic still.

Still not sold on these overhead cam and in this case dual with high horsepower and weak torque.

Guess Germans like Italian love their High revving noise over actual grunt of moving.

Interesting note is that the Quad 4 always had more torque than HP without a turbo and still passed emissions.

Anyone that drove a Quad 4 could feel the grunt of movement in your gut without having to race the sewing machine engine.

Except the Quad4 was a hot mess when it came to oil burn. They were absolute maintenance nightmares when they started acting up. Dated a girl in the 90s who a Calais with that engine. Would not wish that maintenance on my worst enemy. 

 

I do agree about the peak power where the torque is concerned but it’s still no slouch.

Edited June 7, 2019 by surreal1272

[Drew Dowdell]

What I really want to see is the torque curve.... what's the torque output at say 1,500 rpm?  That will say a lot about drivability. 

[smk4565]

7 hours ago, riviera74 said:

Why such low (peak) torque compared to peak horsepower?   This is the opposite of what any engine should be.  It's too bad other automakers' 4cyl engines have the same set of characteristics.  Too bad GM will not build a (non-truck) version of the 3800/3900 to replace the 3.6 V6.  Horsepower is great but torque is actually required.

360ish lb-ft in a front drive car (well all wheel drive) and from a 4-cylinder, that seems like a lot for those circumstances.  Plus an A45 or CLA45 is like a 3400 lb car, not a lot of weight to move.  The 6 and 8 make more torque.

[smk4565]

8 hours ago, Drew Dowdell said:

I wonder if they'll make a longitudinal version. 

I think a better application would be the 306 hp version in longitudinal form.  Because that would be good in the E-class and GLE to have a more powerful 4-banger there, vs the 241/255 hp units they are working with now.  I don't think there would be much demand for a 400 hp, 7200 rpm screamer of a 4-cylinder in an C-class, definitely not in an E or GLE.

Related though, if they can get 400 hp from a 4, they should be able to get 500+ from an inline 6, I think that is an area to explore in pumping the 6 up for the AMG 53's.  There is more in the V8 too, they probably hold these engines back for reliability or emissions.

[Robert Hall]

It's a lot of power for a 4cyl, but it's still just a 4cyl.  

[G. David Felt]

On 6/7/2019 at 10:55 AM, surreal1272 said:

Except the Quad4 was a hot mess when it came to oil burn. They were absolute maintenance nightmares when they started acting up. Dated a girl in the 90s who a Calais with that engine. Would not wish that maintenance on my worst enemy. 

 

I do agree about the peak power where the torque is concerned but it’s still no slouch.

Agree that the Quad had it's problems, Yet it was loved for being a motor that could be turbo'd and pushed to over 1200hp / ft-lbs of torque.

I give props as MB has built a small motor with high HP / torque numbers, yet the Torque is still below the HP and high in the RPM band. This means like a sewing machine engines you have to really rev it to get the performance out of it.

GM on the other hand built plenty of small motors that could move without reeving the hell out of them.

[smk4565]

26 minutes ago, dfelt said:

Agree that the Quad had it's problems, Yet it was loved for being a motor that could be turbo'd and pushed to over 1200hp / ft-lbs of torque.

I give props as MB has built a small motor with high HP / torque numbers, yet the Torque is still below the HP and high in the RPM band. This means like a sewing machine engines you have to really rev it to get the performance out of it.

GM on the other hand built plenty of small motors that could move without reeving the hell out of them.

It is basically like a racing engine, this is tuned for track days and people that want to drive high in the rpm band.   Mercedes makes plenty of engines with low end torque for applications where that makes more sense.  

[G. David Felt]

25 minutes ago, smk4565 said:

It is basically like a racing engine, this is tuned for track days and people that want to drive high in the rpm band.   Mercedes makes plenty of engines with low end torque for applications where that makes more sense.  

Your missing my point, Building a race engine is one thing, we all know MB will put this into as many auto's as they can to recover development cost.

Point being, plenty of quality engines have been built with low end grunt that moves plenty quick with decent hp.

This engine continues what I view as a poor design based on Marketing lies about needing high reving high HP engines with lower torque or very weak torque as most Italian cars have and more and more German cars have.

High RPM to produce the torque does not make an efficient engine.

Proof is in the need to Turbo the heck out of the auto's adding a ton of weight and not really getting any more MPG efficiency out other than a smaller engine for lower tax purposes.

[smk4565]

52 minutes ago, dfelt said:

Your missing my point, Building a race engine is one thing, we all know MB will put this into as many auto's as they can to recover development cost.

Point being, plenty of quality engines have been built with low end grunt that moves plenty quick with decent hp.

This engine continues what I view as a poor design based on Marketing lies about needing high reving high HP engines with lower torque or very weak torque as most Italian cars have and more and more German cars have.

High RPM to produce the torque does not make an efficient engine.

Proof is in the need to Turbo the heck out of the auto's adding a ton of weight and not really getting any more MPG efficiency out other than a smaller engine for lower tax purposes.

This engine is for 3400 lb cars with transverse engine and awd.  Limited to 4 models, A-class, GLA, GLA, and GLB.    0-60 times will probably be 4 seconds, not sure what they need more power than this for in a FWD application for compact cars. 

 What does the competition have in this segment?  Cadillac, Lexus, Acura, Audi all have turbo 4's that max out around 260 lb-ft maybe 290.   Where is the 400 hp XT4?  The 400 hp Lexus NX?  The 400 hp BMW X1?   Mercedes is a country mile ahead here.

[oldshurst442]

58 minutes ago, smk4565 said:

What does the competition have in this segment?  Cadillac, Lexus, Acura, Audi all have turbo 4's that max out around 260 lb-ft maybe 290.   Where is the 400 hp XT4

Possible EV  coming to a theatre near you next summer?  Maybe?

Cadillac IS going all out in EVs, right? 

And...I really DONT want Cadillac selling us A Class, GLA and GLB type vehicles...

[smk4565]

2 hours ago, oldshurst442 said:

Possible EV  coming to a theatre near you next summer?  Maybe?

Cadillac IS going all out in EVs, right? 

And...I really DONT want Cadillac selling us A Class, GLA and GLB type vehicles...

EVs are expensive, and Audi and Mercedes already have 400 hp EVs now and many more coming.  The volume of the luxury market is still in small to mid size crossover.

[oldshurst442]

1 minute ago, smk4565 said:

EVs are expensive, and Audi and Mercedes already have 400 hp EVs now and many more coming.  The volume of the luxury market is still in small to mid size crossover.

Exactly...EVs are expensive...

Like I said...I really dont want Cadillac selling 400 horsepower 4 cylinder XT4s in the first place.   

Maybe an EV XT4 sized vehicle...  Yeah...I could go for that....because then the price tag will be where I want  Cadillac to  be  in...

I could forgo a 400 horsepower 4 cylinder  XT4 V.  If EVs are the future, then 4 cylinder petrol engines are a step back for Cadillac. 

Hey...its impressive those figures...for a 4 banger. Pretty darned awesome.  But, if the market is to shift to EVs, then I want Cadillac looking ahead.  If Tesla could make a name for itself with a Model 3, and the Model 3 is more or less XT4 sized, then I would prefer Cadillac give us a Model 3 competitor rather than what Mercedes is gonna offer with its 400 HP 4 banger. 

Not taking away what Mercedes is doing....Im just wanting Cadillac to be ahead of the curve. 

[smk4565]

Some of these luxury brands are claiming 10 EV's by 2025, so if Cadillac wants to be ahead of the curve, they might as well go all in on EV.

[oldshurst442]

26 minutes ago, smk4565 said:

Some of these luxury brands are claiming 10 EV's by 2025, so if Cadillac wants to be ahead of the curve, they might as well go all in on EV.

That is what I said...and maybe, THAT is what Cadillac's game plan is. I mean, that is what I understood from Mary Barrra's last 2-3 speeches.  

Edited June 9, 2019 by oldshurst442

[ocnblu]

She is a disaster waiting to happen.

 

[dwightlooi]

They didn't move the power band higher up to make the engine more "free revving". That's bullsh!t.

They moved the power band higher up because you can only make so much boost with a turbo before either lag becomes intolerable or detonation sets in. 1.9 to 2.1 bar (28~31 psi) is all they are going to get and one can argue that it is already intolerable -- drive a CLA/GLA45 and you'll see for yourself! It goes like this... full throttle... nothing... coming... buidling... there! Worse yet... Part Throttle... moaning drone... nothing... nothing... coming... starting to build... redline (shift)! Torque is directly proportional to air density (mostly boost) going into the engine. Hence, 350~370 lb-ft is all they are ever going to make. Power on the other hand is a function of torque x rpm. If you want more power, you make that torque higher up. Keep 323 lb-ft around at 6750 rpm and you get 416 hp.

Edited June 17, 2019 by dwightlooi

[dwightlooi]

I'll favor an approach using GREATER DISPLACEMENT and LOWER BOOST. As I have said before in previous threads, the GM 2.7T four potter is an ideal candidate. Keeping the same boost 1.4 bar (20.6 psi) in a properly sized turbo (Eg. G25-550) and a generous air-to-water intercooler -- instead of the undersized and almost falling off the map conch shell they have on it -- will produce about 420 lb-ft (up from 348 lb-ft). This engine won't be a revver with it's 102mm stroke. But, it doesn't have to be; 6,100~6,200 rpm is plenty when you have 420 lb-ft from 2,200~5,200 rpm and 420 hp @ ~5,300 rpm. Hitting the torque peak at 2,200 rpm, however, makes the car a lot easier and enjoyable to drive.

[G. David Felt]

18 minutes ago, dwightlooi said:

I'll favor an approach using GREATER DISPLACEMENT and LOWER BOOST. As I have said before in previous threads, the GM 2.7T four potter is an ideal candidate. Keeping the same boost 1.4 bar (20.6 psi) in a properly sized turbo (Eg. G25-550) and a generous air-to-water intercooler -- instead of the undersized and almost falling off the map conch shell they have on it -- will produce about 420 lb-ft (up from 348 lb-ft). This engine won't be a revver with it's 102mm stroke. But, it doesn't have to be; 6,100~6,200 rpm is plenty when you have 420 lb-ft from 2,200~5,200 rpm and 420 hp @ ~5,300 rpm. Hitting the torque peak at 2,200 rpm, however, makes the car a lot easier and enjoyable to drive.

Totally agree, would take a bigger motor, less boost over smaller, high boost high reving.

[dwightlooi]

4 hours ago, dfelt said:

Totally agree, would take a bigger motor, less boost over smaller, high boost high reving.

I think GM should have two "Grades" of motors -- Standard and Premium.

Chevy and GMC uses the Standard Grade optimized for value and economy. Caddies and Buicks should only use the Premium Grade, optimized for performance and refinement.

The engines can be built on the same production line and share most parts. But the Premium Grade will have things you can never justify to the bean counters for a Malibu or a Silverado. Things like:-

• Individual Throttle butterflies for a snappier response
• Dual Injection with port injection for a quieter idle and cleaner intake valves
• Titanium intake and Sodium filled exhaust valves
• Titanium Aluminide turbine wheels and ball bearing cartridges for marginally better the turbo response and durability
• Air-to-water intercoolers for greater efficiency and lower pressurized volume (better response)
• Forged Steel or Titanium-Aluminide rods and crankshaft.
• Additional acoustic jacket and coverings for a quieter power train
• Magnetorologic Engine and Transmission mounts for better isolation without compromising torque capacity.

 

[smk4565]

4 hours ago, dfelt said:

Totally agree, would take a bigger motor, less boost over smaller, high boost high reving.

A bigger motor may not fit in a small car though so this is what you get.  You can't fit a V8 in an XT4 or a Chevy Sonic.

[dwightlooi]

12 minutes ago, smk4565 said:

A bigger motor may not fit in a small car though so this is what you get.  You can't fit a V8 in an XT4 or a Chevy Sonic.

The 2.7T fits where the 2.5 fitted. It'll fit just fine.

[G. David Felt]

4 hours ago, smk4565 said:

A bigger motor may not fit in a small car though so this is what you get.  You can't fit a V8 in an XT4 or a Chevy Sonic.

People thought a small block V8 would not fit in a Chevrolet Luv Truck and yet plenty of people swapped out the 4 banger for a V8.

 

[dwightlooi]

18 hours ago, dfelt said:

People thought a small block V8 would not fit in a Chevrolet Luv Truck and yet plenty of people swapped out the 4 banger for a V8.

 

Well, plenty of people believe in NONSENSE and that is not limited to automotive matters. As a general rule, a V8 will fit where an I4 will fit in a longitudinal engine bay. This is particularly so given the very compact -- very short and narrow -- nature of a push-rod V8.