Alright, lets do this...
Which segment is the Z4 sDrive35i a part of?
List prices including pre-selected common options in China:
Audi TTS Roadster quattro 272hk - 708,000 RMB (-11%)
BMW sDrive35i 7DCT 306hk - 799,000 RMB (ref)
MB SLK 350 7G-TRONIC 306hk - 898,000 RMB (+12%)
Porsche Boxter S 7PDK 315hk - 970,000 RMB (+21%)
Corvette Stingray Convertible - N/A in China because it would cost +1 million due engine volume tax
What engine is used in all 2009+ Z4 sDrive35i, including the current model year?
The N54 (source
www.bmw.de and realoem.com). Also the above video clearly shows an N54 engine under the hood. The N55 was never used in the Z4.
What is the weight penalty of choosing a hard top over a soft top?
Well we don't know for sure. But certainly not several hundred lbs. I would guess half of the weight difference between the Boxter and the Z4 can be explained by the extra turbos and related cooling, torque etc in a turbo vs NA car.
Weight difference between a well equipped Boxter S and a similar equipped sDrive35is, both with DCT: 1620kg - 1445kg = 175kg = 385lbs (source chinese websites of Bmw and Porsche)
Weight difference between Z4 30i 6MT (3.0L non turbo) and Z4 35i 6MT (3.0L twin turbo) in base-trim: 95kg = 209lbs (source:
http://e89.zpost.com/forums/attachme...1&d=1303133571)
Left is a weight difference of 176lbs between an imagined non-turbo hard top 35i and a similar equipped soft top Boxter s...
Now back to the original topic...