When the Switch to N55 from the N54?

[Chunkaway]

I did a search on this, but there doesn't appear to be a clear answer. When did BMW switch over from the N54 to the N55? 2010? 2011?

I'm asking because I'm of the belief that the N55 single turbos have had fewer issues with the HPFP. But perhaps someone could enlighten me a bit.

Thanks!

[mattjw916]

The 5 series changed to the N55 in 2010; the 1 and 3 series in 2011.

The number of turbos has nothing to do with the fuel pump BTW. The N55s are all very new so if they have problems it's going to take a while before we start to see them.