The fact that BMW has dropped a more powerful engine into the Z4 and created this new 35is can mean only one thing - no Z4 M. If you want big power and a BMW roadster, the 35is is the one you'll have to get.
Still, this version is nearly as powerful as the last Z4 M anyway. You've now got 335bhp and 332lb ft from this twin-turbo straight six, compared to the 338bhp the M version had. The torque figure is actually up on the M by 63lb ft.
The 35is engine is great. The twin turbo-charger means that turbo lag doesn't exist - anywhere above 2,000rpm and you've instant power. And plenty of it too - the 60mph dash only takes 4.8 seconds and it will cruise to 100mph in a blink.
In this Z4, you can only get the dual-clutch gearbox, but that's no bad thing. Changes are smooth and predictable and whether you're in auto or manual, it's effortless.
Driving fast, though, is not at all relaxing. BMW has a sorry history with the way its Z cars handle and this one is no different. Drive Dynamic Control and Adaptive M Sport suspension come as standard in the 35is. You get three settings for the dampers - Normal, Sport and Sport +. Worryingly, the Z4 doesn't feel right in any of them.
In Normal, the rear end is too soft so the car rolls around too much. It feels quite squirmy and is unnerving, to be brutally honest. Whereas in something like an M3 there's an honest and predictable way it lets you know there's an awful lot of power going through the rear wheels, this Z4 doesn't feel as connected to the tarmac or you.
Sport and Sport + do lessen this effect, but the flipside is they make the ride so hard you're in danger of popping your haemorrhoids.
The revised steering doesn't help matters, because it's too vague around the dead centre. When you turn in, the nose doesn't react quickly enough and the back end moves around at the same time. Very disorientating because you're not sure whether to react to the front or the rear.
I don't remember the ‘lesser' BMW Z4s being this bad, probably because the power didn't dwarf the chassis quite so much. Good job there's no M coming then.
On your drive for: £1,091pcm
Performance: 0-62mph in 4.8secs, max speed 155mph, 31.4mpg
Tech: 2979cc, 6cyl, RWD, 335bhp, 332lb ft, 1580kg, 210g/km CO2