Like I said earlier:
every engine line will have NA and turbo versions.
NA will be entry-model engines of engine line (eg. NA I4, NA I6, NA V8, NA V12), while turbos will replace top-model engines (the ones with higher dispalacement) in the line - and will be bridges to the highe model of engine.
Eg. (just an example! fiction data!):
NA 1.6L I4 ... turbo 1.6L I4 (replacing 1.8L NA I4)
NA 2.0L I4 ... turbo 2.0L I4 (replacing 2.5L NA I4)
NA 3.0L I6 ... turbo 3.0L I6 (replacing 4.0 V8 NA)
NA 4.4L V8 ... turbo 4.4L V8 (a bridge to V12 NA)
NA 6.0L V12 ... turbo 6.0L V12 (eg. for RR performance models)
Yet maybe in US detuned NA I6 will be offerd instead of turbo I4, since a 4-cylinder engine in 3er could hurt its upmarket image. But 2er will get I4 turbo in US as well.
Also various settings are possible: so there could be eg. two versions of NA 2.0L I4 - one standard, one detuned. Etc. And same could happen with turbos - having different settings.
"iS" version of X5 will come soon after engine will be available. And engine will be available in 2008.
