RLE

My January 29 subscription issue of auto motor und sport from Stuttgart arrived today. It contains a road test picture article of the new C350 CGI Blue Efficiency. The engine is the 3.5 direct injection version (finally) with 292HP. It uses new cylinder heads with piezo injectors.The exterior looks the same as current Sport models with the new mirrors plus Parktronic and P2 on the test car.

Pictures taken through the driver's door show:

The test car had the multicontour seats with the power seat controls down on the seat side (just like the US '08 models) with a big round wheel forward of that to adjust the seat bolsters.

There is a fuel consumption bar in the upper half of the speedo, just like the other Blue Efficiency models.

The instruments are NOT hooded.

The top of the dash has been reshaped. The central speaker square is about where it was but on each side under the windshield, the speaker grills are more vertical which lowers the dash top a little below them. There is a Blue Efficiency medallion on the central speaker grille, similar to those on the front fenders.

Test fuel mileage was 11.1 L/100 km (only .4 Liters better than the same engine in an E-Class.

0-100 km is reported at 6.3 seconds, 10% better than the previous C350.

Keep in mind, this is a Euro model in a German magazine and whether or not it will come to the US is unknown.

Untertürkheim

The W212 will only have direct injection engines for Europe (except V8 models, still IDI), but the US will not see any of those engines, including the 350CGI, because our gasoline is too high in sulfur. I doubt the C would get it without it being in the E or S400.

Diesel Benz

I always thought sulphur was an issue for Diesel fuel only but now I've seen this same mentioned several times for gasoline too. Sounds like it would be a bigger investment to have the fuel supply chain modified for low sulphur gasoline compared to the similar move for diesel?

amdeutsch

Makes one wonder what they use in the SLK350. It has a 300hp 3.5 V6 for MY09 listed on MBUSA.

http://www.mbusa.com/mercedes/#/expl...yr=2009&vc=SLK

But in typical MBUSA fashion it also lists it as 268hp.

http://www.mbusa.com/mercedes/#/expl...yr=2009&vc=SLK

But yet when you click on the V6 at the right it pops up with a pic showing once again 300hp.


MBUSA =

RLE

So your theory is that gasoline direct injection is not possible using US gas. Please explain, then, all the other DI engined cars, both German and Asian that are being sold here now. Using the same piezo injectors, by the way.

Shall I name them?

FrankW

damn the CGI..i'm hating! lol

Untertürkheim

Actually, the SLK350 does not use DI, the increased power and torque are a result of higher compression and more aggressive cam profiles.

Untertürkheim

It is actually not a theory, it is the statement issued by MB as to why the US will not get the DI engines.

nyca

Indeed, this "dirty gas" is total BS from MB. They must have a ton of 268HP 3.5 engines in the supply chain, so many that even the new W212 isn't getting a new engine.

They are stringing this out to the very end, when they will need those DI engines to meet MPG/CO2 standards, until then they will sell what they have.

Audi, Porsche, even Cadillac are all running DI engines.

Bokx_350

How is 6.3s 10% better than the previous C350?

isn't the official 0-100 time for the regular c350 6.4s?

I'm kind of dissapointed at that 0-100 time from the 292hp.

RLE

And Isuzu. Here.

I'd like to see that MB document. Yes, all Porsches are now DI.

FrankW

295-300hp should easily be in the mid 5's.

I blame the stupid 7-tronics. lol

RLE

The article says the old engine acceleration number is 7 seconds. Your official source is perhaps the owners manual?

FrankW

nope, the MB-Germany site listed 0-100 for C350 is 6.4 and C350 CGI as 6.2 second. The article is wrong.

I think the reason for not much 0-100 improvement is because that the increase of 20PS and 15NM torque also raised the useful torque range from the previous 2400-5000 to 3000-5100rpm while looking at the gear ratio they're exactly the same down to final drive. peak HP also went up from 6000 to 6400.

TRauppius

Attached are a few MB photos of the CGI 350 engine and the high pressure fuel distribution and fuel cooler assembly.

The system uses a secondary, high-pressure, fuel pump prior to fuel distribution to the individual cylinder injectors which use piezo-electric technology to boost the fuel pressure high enough to override the residual/building pressure in the combustion chamber during the compression stroke. The secondary fuel pump has the effect of raising the temperature of the gasoline to problematic levels. This is managed by adding a fuel cooler (shown nestled to the side, rearward of the oil filter assembly, see photo).

Now, note the inlet and outlet lines to the fuel cooler. Where/what is the cooling source or heat sink that these lines are connected too? It appears that the plumbing may be connected/tapped-into to the air-conditioner coolant loop. This would yield enough cooling to moderate the fuel temperature as I suspect that the water or oil systems are just too hot to serve as a fuel cooler heat sink. Maybe there is another radiator somewhere.

In any event, the fuel cooler has the potential to introduce some parasitic power losses and slight weight gain that could slightly mitigate some of the combustion efficiency gains. The MB CGI scheme seems to setup to maximize efficiency rather than increase volumetric power output.

Star & Laurel

The '09 SLK 350 making ~300 Hp is a result of changes to the engine. Different exhaust and intake manifold along with tuning I'm sure. This is still a traditional port fuel injection setup.

FrankW

read above. SLK350 made 300hp from re-mapping and new cams and raised the redline with higher compression.

eventually this will be the C350 engine, but we probably have to wait till June or July to see the 2010 MY.

RLE

Wrong is not the word. The AMS numbers were THEIR test numbers. Performance numbers can be affected by a lot of factors. Driver technique, air temperature and humidity, altitude and so on.

But the fact remains, more horsepower means better performance. The real question remains. Why is MB still dithering when other manufacturers have DI engines in service, here in the US? Excuses, excuses.

RLE

And there is a 316HP version in the Euro only SL350. Not DI. Exhaust differences, most likely.

FrankW

i stand corrected. MB's official numbers are tested in controlled environment most of the time tho. also, the official time are usually more conservative.

Star & Laurel

My source stated that the 350's making more power also have modified intakes and exhaust packages. Yes compression has been raised and I'm sure they change cam profiles for adapt to the modified air flow. But I have been told the ~300 hp 350s have plastic / composite intake manifold compared to our aluminum manifolds. Anyone can confirm that.

Actually just did it myself. '09's use manifold A272 140 24 01 and '08's use A272 140 30 01