Mercedes new four-cylinder diesels

[Dinnie]

http://www.carmagazine.co.uk/News/Search-Results/Industry-News/Mercedes-new-four-cylinder-diesels/

One of the reviewers is correct, the magazine is comparing the new MB diesels against the older single diesel turbo engines from BMW rather than the newer versions as found in the *23d and *35d models.

 

[gmcelroy]

The figures for the new MB engines are good, but not "cutting edge" - All of these new engines only narrow what was a large gap between themselves and BMW. Since BMW already have proven their twin turbo engines, the x23d engine will probably make the writer of that review eat his words

Comparison:

200CDI – 134bhp/243lb ft vs 318d - 143bhp/60.1mpg/123g CO2
220CDI – 168bhp/295lb ft vs 320d - 177bhp/58.9mpg/128g CO2
250CDI – 201bhp/369lb ft vs 123d - 204bhp/54.3mpg/138g CO2

So C250CDI with 201bhp, 143g CO2 and 51mpg isn't really going to worry BMW, although its a big improvement over the current MB units. I've driven the C220CDI and its a nice engine, but not as refined as the latest 2.0ltr Efficient Dynamics BMW unit.

 

[st4]

IIRC BMW diesels have a high rate of Turbo failure, mainly because of high boost pressure. I'd rather have an engine that was less powerful but was more reliable.

On the whole Merc diesels do not give nearly as much trouble as the BMW ones, I'd take the former.

 

[gmcelroy]

Yep, the early BMW diesel engines have suffered with turbo issues and the "swirl flap problem" - That was on the 150bhp engine in the E46. They also had a batch of turbo's recently with faulty electronic acctuator units, but most of these have been relatively minor warranty issues and given the number of these on the road the failure rate wasn't that high (although as a customer any failure is one too many But from an engineering perspective these things do happen).

On the MB side I've read quite a few threads on turbo or injector issues with the MB diesels as well - both in cars and in the vans as well. With modern high pressure diesels I think small numbers of these kind of failures are almost inevitable due to the fine tolerances involved. Hopefully other manufacturers will follow the lead of BMW and MB in creating more efficient powerplants, as I'm supprised how many so called "modern" engines in recently released cars are comparatively inefficient and CO2 heavy.

 

[NewMB]

At last MB is catching up!

With such a powerful 4 cyl engine (ie 201 Bhp) makes you wonder what will happen with the current 320Cdi. My C class has 224 bhp in standard form (well, 272 bhp with Brabus chip) and 208 CO2.... hopefully they can make a new one with more power and less CO2 to match those of the 4 cylinder.