Mercedes Benz DiesOtto inline-4 engine concept

Mercedes Benz DiesOtto Diagram
Click image above to enlarge diagram view

DaimlerChrysler has revealed details on what could be the successor to the current 1.8 litre E18 M271 used as Mercedes Benz’s flagship inline-4 engine. Quite a few car manufacturers have been combining the best qualities of both a petrol engine and a diesel engine, and this is DaimlerChrysler’s attempt called the DiesOtto concept.

This 1.8 litre DOHC inline-4 engine with variable valve control can produce 238 horsepower and 400Nm of torque, but consumes less than 6 litres of fuel per 100km – not on a small car but in the current Mercedes Benz S-Class!

Instead of the M271’s Kompressor supercharging, the DiesOtto uses turbocharging combined with direct injection. Now this is where the diesel characteristics come in – there is a special controlled auto ignition mode during low to medium engine speeds on low loads which ignites the air-fuel mixture through compression alone without spark ignition – this is called homogeneous combustion. For better emissions, the DiesOtto engine has a standard three-way catalytic converter

The DiesOtto will not be available in the market anytime soon, instead DaimlerChrysler will slowly be adding features from the DiesOtto concept to it’s production inline-4 engine one by one until the full concept is realised.

Technologies such as direct injection are already in production, and my guess is the next step would be for the Mercedes Benz inline-4 engines to go the turbocharging route instead of using a supercharger.

Have a look at the related posts below to read about engines with similar concepts being developed by other car manufacturers.

Related Posts:
Homogeneous Charge Compression Ignition
Volkswagen gives sneak preview of future engine projects
Mercedes Benz inline-4 engines: M266 vs M271

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Paul Tan

After dabbling for years in the IT industry, Paul Tan initially began this site as a general blog covering various topics of personal interest. With an increasing number of readers paying rapt attention to the motoring stories, one thing led to another and the rest, as they say, is history.

 

Comments

  • ys (Member) on Jul 26, 2007 at 9:31 am

    very impressive engine and the house power / torque.. awesome for a 1.8liter machine dude.
    6 liters for 100km is among the best in this category.
    RM1.92×6 = RM11.52/100km ~ RM0.115 per km.
    come close to 1liter engine fuel consumption.

    i would say this will bring big impact to the autoworld as ppl now talking about hybrid etc…
    Good job Mecs.. but what will be the price? not many malaysian can affort this laa.

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  • szw (Member) on Jul 26, 2007 at 9:49 am

    yet , its not an award winnig 5.0L engine…

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  • Paul Tan on Jul 26, 2007 at 9:50 am

    szw: that is because it does not exist yet

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  • BanyakMasukWorkshop (Member) on Jul 26, 2007 at 2:36 pm

    fantastic engine ;)

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  • silverfish (Member) on Jul 26, 2007 at 3:11 pm

    Award winning engines are for engineers and geeks to wank over. It doesn’t necessarily equate to better (relatively) consumer experience.

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  • proton.GL.. (Member) on Jul 26, 2007 at 3:49 pm

    -from car scoop-
    “Like most European automakers, Mercedes has already accomplished creating economical diesel units as clean and as powerful as gasoline engines. Now Mercedes’ next goal is to make the gasoline engine as frugal as a diesel unit. The “DiesOtto” concept, which incorporates the foremost strengths of both the petrol and diesel engines, is the first step towards that goal. The DiesOtto’s package includes technology features such as direct gasoline injection, turbocharging, a variable compression ratio, a hybrid module with an integrated starter/generator and most importantly, the controlled auto ignition, a highly efficient combustion process similar to that of a diesel.”———carscoop-july 25th 07

    —————————————–
    proton GL said,
    April 17, 2007 @ 4:19 pm
    cold start combustion is easily resolve with some kind initial ignition, or glow plug, etc.
    my doubt is the capabilty for higher speed engine, theres a posibility a preignition happened before TDC due to heat built up, which destruct the engine,
    due to non regulated ignition, they might want to have somekind of variable copression ratio in relation with engine speed or load, perhaps a small clyinder/piston built in the chamber to alter volume of the chamber hence the reduce the comp ratio for extreme condition,
    —-(previous discussion found pauls rave and rants,)
    —————————————————————-

    so,suprisingly Mercedes did say about ‘variable compression ratio’ which make possible of controlled auto ignition, and sparkplug ignition under load variation of engine load, (lower compression tuned for spark plug ignition when engine in higher load )
    just wonder how they execute this variable compression ratio mechanically ..

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  • ingolstadt (Member) on Jul 26, 2007 at 11:38 pm

    fantastically rough engine i would assume.

    BTW Paul, DaimlerCHRYSLER ? Ain’t it shold to Cerberus? Should be Daimler Benz again right?

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  • Paul Tan on Jul 27, 2007 at 3:51 am

    ingolstadt: they have not legally changed their name yet, so it remains daimlerchrysler

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  • jamsbong (Member) on Jul 27, 2007 at 4:23 pm

    One of the easy way to reduce compression is to delay the intake valve timing. so effectively you’ll get smaller capacity output. However, judging from the incredible power output. I also wonder if they are using some other technique.

    It seems that petrol direct injection is off, if you guys seen the complicated system that is employed in a volkswagen FSI, you’ll really question why go through so much trouble?

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  • proton.GL.. (Member) on Jul 27, 2007 at 5:48 pm

    good idea jamesbong,
    but under engine heavy load/high revs the fuel injection occured during intake stroke,
    if delaying intake valve closure during compression stroke it might pump out some of the mixture to the intake manifold,
    well this works fine in miller cycle engine since its the intake manifold is in pressurised by the supercharger,

    this is self ignited combination, is to belived more fuel saving then direc injection,
    thats why they re trying,
    but i agree with you, it add to the complexity, since compression ratio need to be varied, while its not needed in direct injection,

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  • Pierre on Jun 25, 2010 at 5:58 pm

    marketing horsepower and number, basically a diesel engine is HCCI ready with a larger torque reading, it wouldnt be such a worry to run diesels had the manufacturers gone hondas way or utlizing aluminium to close the engine weight gap between diesel and petrol engines.to give a more acceptable imagine to the petrolheads. aluminium too requires more wall thickness and is softer than iron resulting in better knock sound dampening or absorbing…the hcci is complicated, critical and sporadic in nature…very very unstable yet volume for volume a diesel will still produce high brake means effective pressure…although not horspower since it is slow burning resulting in limited rpm

    just look at jaguars numbers;
    Jaguar XF 3.0 Diesel S Portfolio. Engine 2993cc, V6. Power 275bhp @ 4000rpm. Torque 442 lb ft @ 2000rpm.

    Performance: 5.9sec 0-62mph, 155mph, 42.0mpg

    ahead of the desotto….again….a hevy engine

    borneo

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  • thank you for the images shown.

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  • Noel Renson on Feb 17, 2013 at 7:57 pm

    Hi everybody . is simebody here knows which variable compression system the DIESOTTO use ? Is it a “old” system improved ? Or a new one ? Thanks . Noel

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