Automobile Magazine has tweeted the following:

>BMW new 4-cyl coming this year in Z4 roadster. Replaces nat asp 6, so at least 200 hp

It sounds right to us. Here ‘s the logic. We know that the 28i model in all BMWs will be changing over to a turbo four in the years ahead. In fact we ‘ve done so much as say that the current 328i will be the last naturally aspirated 3 series for the foreseeable future. And course that should also extend to all BMW models with that engine. So why the Z4 first? It ‘s been in production the longest of all the current generation cars that will see the update so it makes sense to start there. But what other cars would get the turbo four cylinder? We ‘re guessing the F10 5 Series, F30 3 Series and of course the forthcoming F20 1 Series.

What about output? We would expect power ratings to be very similar to the 230 hp inline six in a package that is somewhat lighter. Perhaps just as important fuel efficiency should be noticeably better.

Timeframe? We ‘re guessing this change will happen either in the fall or next March to at least one model.