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World Premiere Of The Mercedes CLS 350 CGI

Posted by www.eMercedesBenz.com on February 24, 2006 at 8:40 AM CST

Mercedes has announced today that they will be adding a new member to  
the CLS family, dubbed the Mercedes-Benz CLS 350 CGI.

The CLS 350 CGI, or Stratified-Charged Gasoline Injection if you're  
not the acronym-inclined type, is the world's first vehicle sporting  
a petrol engine to feature piezoelectric direct injection and spray- 
guided combustion.  Or in plain English, the CLS has more power than  
a conventional CLS 350, all while consuming less fuel.  Sound too  
good be to true?  Read on my skeptics.

First up are the specs. The Mercedes CLS 350 CGI is powered by a 215  
kW/292 hp six-cylinder engine, producing a torque rating of 365  
Newton metres at 3000-5100 rpm.  That's an increase of 20 horsepower  
over the conventional-injection V6 and four percent more torque.  In  
terms of on-road performance, the CLS 350 CGI accelerates from 0-60  
in 6.7 seconds, and can reach an electronically limited top speed of  
155 mph.

But as promised, despite the impressive numbers, the newest CLS also  
features improved fuel economy.  According to the press release,  
owners can expect to see approximately 9.1 - 9.3 liters per 100  
kilometers, which gives the four-door coupe a range of about 807  
kilometers on one tank filling (80 Liters).  For my American readers,  
that comes out to about 25 mpg, an increase in fuel economy of up to  
15% over the standard CLS 350.

This all sounds great, but you're probably wondering how the new  
injection system works. Fear not my faithful readers, here's a small  
sample from taken the press release that should give you some idea of  
what's going on under the hood:  "The main advantage of the CGI  
engine lies in the stratified operating mode from which it takes its  
name. During this mode the engine is run with high excess air and  
thus excellent fuel efficiency. Now, thanks to multiple injection, it  
is for the first time possible to extend this lean-burn operating  
mode to higher rpm and load ranges too. During each compression  
stroke, a series of injections takes place, spaced just fractions of  
a second apart. This has the effect of significantly improving  
mixture formation, combustion and fuel consumption. While stratified  
charge operation was previously only possible in the low part-load  
range, the new Mercedes direct-injection engine can still operate in  
this lean-burn stratified mode at speeds in excess of 120 km/h."

Got that?  Of course, that's only a small sampling of what you can  
expect from the press release.  Visit www.eMercedesBenz.com for  
photos of the new Mercedes CLS 350 CGI as well as the new CGI  
injection system, and check out the press release below for the full  
details of how the new system works.  Oh, and by the way - expect to  
see the CLS 350 CGI hitting European shores in the second quarter of  
2006.

Enjoy.


OFFICIAL PRESS RELEASE


World premiere of an innovative direct petrol injection system: Ten  
percent lower fuel consumption with more output and even more driving  
pleasure

Stuttgart, Feb 24, 2006

Following intensive development work, Mercedes-Benz is now presenting  
the world's first petrol engine with piezoelectric direct injection  
and spray-guided combustion. This 215 kW/292 hp six-cylinder engine  
will enter the market in the second half of 2006 in the CLS-Class. In  
the European driving cycle, this innovative injection technology from  
Mercedes-Benz achieves fuel consumption improvements of ten percent  
over the highly efficient V6 petrol engine with port injection and  
fully variable valve timing: the figures for the CLS 350 CGI are 9.1  
litres per 100 km. Thus Mercedes-Benz has succeeded in combining a  
substantial increase in output with a significant increase in fuel  
economy.

This pioneering injection system is another trend-setting technology  
from Mercedes-Benz. It achieves much better fuel efficiency, and thus  
also higher thermodynamic efficiency, than conventional wall-guided  
direct injection systems. The new system will form the basis for  
future engine development work in this output class.

The main advantage of the CGI engine (CGI = Stratified-Charged  
Gasoline Injection) lies in the stratified operating mode from which  
it takes its name. During this mode the engine is run with high  
excess air and thus excellent fuel efficiency. Now, thanks to  
multiple injection, it is for the first time possible to extend this  
lean-burn operating mode to higher rpm and load ranges too. During  
each compression stroke, a series of injections takes place, spaced  
just fractions of a second apart. This has the effect of  
significantly improving mixture formation, combustion and fuel  
consumption. While stratified charge operation was previously only  
possible in the low part-load range, the new Mercedes direct- 
injection engine can still operate in this lean-burn stratified mode  
at speeds in excess of 120 km/h.

When driving on main roads and motorways at largely constant speed  
and with proper anticipation, the CGI engine outperforms the fuel  
economy of the six-cylinder engine with conventional injection  
technology by up to 1.5 litres per 100 km, a saving of up to 15 percent.

Effortless performance twinned with excellent fuel economy

Low fuel consumption and excellent power delivery are not at odds  
with each other on the second-generation Mercedes-Benz direct petrol  
injection model. On the contrary, the engine delivers 15 kW/20 hp  
more power than the conventional-injection V6 and four percent more  
torque.

Thus the V6 combines its excellent fuel economy with a level of  
effortless driving enjoyment that is unprecedented in the six- 
cylinder segment. The CLS 350 CGI accelerates from 0 - 100 km/h in  
just 6.7 seconds and has an electronically gov-erned top speed of 250  
km/h. The key figures for the new CGI engine are:

Displacement:   3498 cc
Compression ratio:   12.2:1
Rated output   215 kW/292 hp at 6400 rpm
Rated torque   365 Newton metres at 3000-5100 rpm
With a fuel consumption of 9.1 - 9.3 litres per 100 kilometres (NEDC  
combined cycle), the four-door Coupé has a range of approximately 870  
kilometres on one tank filling (80 litres).

Pioneering invention: outward-opening piezoelectric injectors

The most important components of this innovative direct petrol  
injection system are the fast-acting, high-precision piezoelectric  
injectors. It is on this invention and the way it has been translated  
into series-production technology that the most important advances  
associated with spray-guided combustion are based. The piezoelectric  
valves have injectors which open outwards to create an annular gap  
just a few microns wide. This gap shapes the fuel jet and produces a  
uniform, hollow-cone-shaped spray pattern. The microsecond response  
times of the piezoelectric injectors provide the basis for delivering  
multiple injections per compression stroke, and thus for lean-burn  
operation. By allowing flexible and efficient control of the  
combustion process they play a key part in ensuring the engine's  
outstanding fuel efficiency.

With the aid of simulations for the fuel mixture and the combustion  
process, the pistons have been designed with special piston bowl  
geometry which concentrates the lean mixture in the area around the  
spark plug and prevents it from spreading out towards the cylinder  
wall. The piston shape therefore also plays its part in ensuring near- 
total combustion, low fuel consumption and low emissions in the  
direct-injection petrol engine.

A high-pressure pump and downstream fuel rail and pressure control  
valve are responsible for delivering the fuel and regulating the  
quantity supplied. The peak fuel pressure in this system is up to 200  
bar - around 50 times the fuel pressure in a conventional petrol  
injection system.

Dual effect: low engine-out emissions and high exhaust temperatures

The Mercedes-developed combustion process featuring multiple closely  
spaced injections on each compression stroke also results in smoother  
operation and improved emissions performance. Measurements show that  
engine-out hydrocarbon emissions in the warm-up phase are almost  
halved. Furthermore, since the injection and combustion processes can  
be actively controlled, it is also possible to raise temperatures in  
the exhaust manifold and thus speed catalytic converter warm-up. Just  
ten seconds after starting from cold, the direct-injection petrol  
engine reaches an exhaust temperature of over 700 degrees Celsius.

Emissions are controlled by two close-coupled three-way catalytic  
converters with linear oxygen sensor control, which goes into  
operation immediately after the engine starts from cold.

To reduce nitrogen oxide emissions, Mercedes-Benz has adopted a two- 
part strategy. This comprises, firstly, dual electrically controlled  
and cooled exhaust gas re-circulation which, depending on engine  
operating conditions, redirects up to 40 percent of the exhaust gases  
back into the cylinders. Secondly, it also comprises two underfloor  
NOx storage-type catalytic converters. Under lean operating  
conditions, these converters adsorb the nitrogen oxides.  
Periodically, during brief regeneration pulses, the nitrogen oxides  
are then desorbed, reacting with other exhaust gas constituents to  
form harmless nitrogen. Sensors upstream and down-stream of the  
catalytic converters monitor their operation.

In addition, the new CGI engine also incorporates the same unique  
package of high-tech features as its conventional-injection  
counterpart. This includes four-valve cylinder heads, variable intake  
and exhaust camshaft timing, a two-stage in-take manifold, balancer  
shafts and intelligent thermal management with an electronically  
controlled thermostat. The crankcase and cylinder heads are of  
aluminium and the cylinder liners are of low-friction, thermally  
resistant, lightweight aluminium-silicon alloy.

All fuel-carrying components of the CGI engine are of high-grade  
steel or brass; the rails in the area of the two cylinder banks and  
the housing of the high-pressure pump are of forged stainless steel.

The new CLS 350 CGI is designed to operate on sulphur-free unleaded  
premium fuel and its state-of-the-art technology gives it the  
potential to adapt to emissions standards of the future. In Western  
Europe, the CLS direct petrol injection model will replace the  
current CLS 350.

For more Mercedes-Benz news and information, visit  
www.eMercedesBenz.com.