For some time, the diesel engine hit a rough wind. In the whole discussion about the sometimes defective exhaust gas aftertreatment with regard to nitrogen oxides, sometimes almost a little under, why some manufacturers are so brave on the self-cord. He is still a probate means to reduce fleet consumption. Now that was not necessarily allowed to be the first goal when it has gone around the development of the second M550D, but BMW has certainly been in view. The result is a series socket cylinder – yes, there is still something with BMW – with three liters displacement and four turbochargers.
Already the BMW M550D introduced 2012 brought some a grave. Three turbocharger helped the three-liter six-cylinder to 381 hp and 740 nm. In the current ie it is with 400 hp and 760 nm again slightly more. So much pleasure such a potent powertrain also likes: woe if it hooks in the complex interaction of the step charging somewhere. The then circling revision costs were allowed to serely shock evenly warranty and goodwill also Trager well-known wallets.
In the second edition there is now a loader more. Two compact turbocharger covers prere in the lower speed range. Due to the small rough, they are already talking to low exhaust gas quantity and deliver prere. Practically from slightly increased idling speed are already available more than 450 nm. It is new that there is two rough turbochargers for the upper speed range – so far it was only one. There, a connection flap at less than 2700 / min held the fresh air from the third loader already active in this speed range to avoid prere fluctuations. Now one of the two coarse turbocharger always runs, while the other is slowly supplied with exhaust at 2500 / min.
In the long term, there will no such a collection of turbochargers. The manufacturers will probably be more likely to help the internal combustion engines in their design-related weak phases with electric motors on the sponge. This is not necessarily easy, but the development effort is so easier to distribute a certain amount of cars. At BMW, of course, there will still be a lot of engines with more than a turbocharger. Finally, the next BMW 1er with front drive and transverse motors gets maximum two-liter four-cylinder. If BMW does not want to lose the previous six-cylinder clientele, they will have to make the four-cylinder abundant prere. How that could go out, let’s admire today – in the Mercedes A 45 AMG.
The exhaust prere in the M550D, which was formerly provided only for the high prere area, was also considered for those in which the small turbos were active. Now they also have them in the low prere area, that is, that in which the two coarse turbocharger is provided with exhaust gas. BMW promises a high degree of efficiency of the loaders and of course less emissions. This should also contribute a high injection prere, because the fuel is dusted so beer. BMW remains with piezo injectors, while in the folk models like the 320d now again working solenoid valve injectors. So far, the maximum injection prere in the M550D was 2200 bar, now it is up to 2500 bar. Thus, BMW is the same level, such as Volvo in the current diesel engines or Audi in SQ7. That may have technical reasons, no one dares. Presumably a border is achieved in which further increases in any relevance are more complex handling.