The DiesOtto motor is an experimental

automobile engine , there were a wide variety of propulsion systems available or potentially available for automobiles and other vehicles. Options included internal combustion engines fueled by petrol, diesel, propane, or natural gas; hybrid vehicles, plug-in hybri ...

that "is said to incorporate the benefits of a diesel engine, but runs on

gasoline Gasoline (; ) or petrol (; ) (see ) is a transparent, petroleum-derived flammable liquid that is used primarily as a fuel in most spark-ignited internal combustion engines (also known as petrol engines). It consists mostly of organic co ...

instead." Its name is a

portmanteau A portmanteau word, or portmanteau (, ) is a blend of wordsDiesel engine The diesel engine, named after Rudolf Diesel, is an internal combustion engine in which ignition of the fuel is caused by the elevated temperature of the air in the cylinder due to mechanical compression; thus, the diesel engine is a so-call ...

, first introduced by German engineer

Rudolf Diesel Rudolf Christian Karl Diesel (, ; 18 March 1858 – 29 September 1913) was a German inventor and Mechanical engineering, mechanical engineer who is famous for having invented the diesel engine, which burns diesel fuel; both are named after him. ...

, and the

Otto cycle An Otto cycle is an idealized thermodynamic cycle that describes the functioning of a typical spark ignition piston engine. It is the thermodynamic cycle most commonly found in automobile engines. The Otto cycle is a description of what happ ...

, as a reference to

Nicolaus Otto Nicolaus August Otto (10 June 1832, Holzhausen an der Haide, Nassau – 26 January 1891, Cologne) was a German engineer who successfully developed the compressed charge internal combustion engine which ran on petroleum gas and led to the mode ...

(even though the invention of the

gasoline engine A petrol engine (gasoline engine in American English) is an internal combustion engine designed to run on petrol (gasoline). Petrol engines can often be adapted to also run on fuels such as liquefied petroleum gas and ethanol blends (such as ''E ...

is variously attributed to both Nicolaus Otto and

Alphonse Beau de Rochas Alphonse Eugène Beau de Rochas (9 April 1815, Digne-les-Bains, Alpes-de-Haute-Provence – 27 March 1893, Vincennes) was a French engineer. He was the first to patent the four-stroke engine in 1862, but he did not build one and the idea was sub ...

). As of 2017, the only company which announced to launch a car with a DiesOtto motor is

Mazda , commonly referred to as simply Mazda, is a Japanese multinational automotive manufacturer headquartered in Fuchū, Hiroshima, Japan. In 2015, Mazda produced 1.5 million vehicles for global sales, the majority of which (nearly one m ...

, with SKYACTIV-X.

Engine characteristics and principles of operation

The concept engine has an in-line, four-cylinder configuration and displaces 1.8 litres. Its peak power is no less than , making its specific output 97 kW/L (130 hp/L), and its peak torque is 400

N·m The newton-metre (also newton metre or newton meter; symbol N⋅m or N m) is the unit of torque (also called ) in the International System of Units (SI). One newton-metre is equal to the torque resulting from a force of one newton applied ...

, making its specific torque 220 N·m/L. Mercedes-Benz do not specify the RPM at which these specified maxima are reached.Mercedes-Benz unveils DiesOtto - the "future of the gasoline engine"
/ref> The DiesOtto features the following: *

homogeneous charge compression ignition Homogeneous Charge Compression Ignition (HCCI) is a form of internal combustion in which well-mixed fuel and oxidizer (typically air) are compressed to the point of auto-ignition. As in other forms of combustion, this exothermic reaction releases e ...

(HCCI); *

variable valve timing In internal combustion engines, variable valve timing (VVT) is the process of altering the timing of a valve lift event, and is often used to improve performance, fuel economy or emissions. It is increasingly being used in combination with varia ...

; * twin variable geometry turbocharging; *

variable compression ratio Variable compression ratio (VCR) is a technology to adjust the compression ratio of an internal combustion engine while the engine is in operation. This is done to increase fuel efficiency while under varying loads. Variable compression engines allo ...

; *

direct fuel injection Fuel injection is the introduction of fuel in an internal combustion engine, most commonly automotive engines, by the means of an injector. This article focuses on fuel injection in reciprocating piston and Wankel rotary engines. All compr ...

. It also uses a starter-alternator to reduce fuel consumption. The starter-alternator replaces the engine's

flywheel A flywheel is a mechanical device which uses the conservation of angular momentum to store rotational energy; a form of kinetic energy proportional to the product of its moment of inertia and the square of its rotational speed. In particular, ass ...

, and allows the engine to be started instantaneously so that it can simply stop when not needed, such as at traffic lights, and smoothly restart when needed. In low-demand conditions (low to medium engine speeds), the engine uses HCCI. In high-demand conditions, it operates like a regular gasoline engine (using spark ignition of the fuel/air mixture) and uses the full benefits of direct fuel injection, turbocharging and variable valve timing to maximize efficiency. These two modes of operation require different compression ratios, achieved via a concept similar to that of the Lanchester shaft, which is why the engine also features a variable compression ratio. It is reported to consume less than when fitted to the S-Class demonstration vehicle. However, it is unknown in what conditions this mileage is achieved.

Testing and demonstration

The testing and demonstration vehicles include a long-wheel based

Mercedes-Benz S-Class The Mercedes-Benz S-Class, formerly known as ''Sonderklasse'' (German for "special class", abbreviated as "S-Klasse"), is a series of full-sized luxury vehicle, luxury sedans, limousines and Armored car (VIP), armored sedans produced by the Germa ...

fitted with a

electric motor An electric motor is an Electric machine, electrical machine that converts electrical energy into mechanical energy. Most electric motors operate through the interaction between the motor's magnetic field and electric current in a Electromagneti ...

to hide the transition from spark to compression power, and the engine has been installed in the

Mercedes-Benz F700 The Mercedes-Benz F700 is a concept car produced by Mercedes-Benz in 2007. It was first revealed to the public at the 2007 Frankfurt Motor Show. It was given as a gift to UAE The United Arab Emirates (UAE; ar, اَلْإِمَارَات ...

concept car shown at the 2007

Frankfurt Motor Show The International Motor Show Germany or International Mobility Show Germany, in German known as the ''Internationale Automobil-Ausstellung'' (''IAA'' – International Automobile Exhibition), is one of the world's largest mobility shows. It cons ...

References

{{Reflist

External links

Pictures for Mercedes concept DiesOtto Car
Mercedes-Benz engines Automobile engines