The prospect of a super-frugal BMW Z4 looks increasingly doubtful after BMW admitted it's unlikely to offer a diesel version of the current-generation roadster.
Project leader Ingo Lasslop told What Car?: 'I can't see it especially after the launch of the new [petrol] sDrive18i model.'
However, it's believed that fitting BMW's current-generation four-cylinder diesel engine in the Z4 might not be as straightforward as originally thought.
Furthermore, the Z4 already weighs around 150kg more than an equivalent Audi TT Roadster, and a diesel engine would add around a further 30kg.