06 Jul 06
The Z4 3.0si is more closely-matched to the new entry-level Cayman and it's not exactly slow.
With its lightweight 3.0-litre, 265bhp straight-six engine, it's capable of 155mph (electronically limited to the same level as the Z4 M) and 0-60mph in 5.7 seconds, just 0.7 seconds slower than the Z4 M - and a thoroughly respectable sprint time by any standards. And with prices from £31,400, it looks better value than the less powerful Cayman (245bhp, 0-60mph in 6.1 seconds, £36,220). Should you need any further persuasion of its cost-effectiveness, this model also does 31.7mpg.
Though it retains the same low-slung, purposeful road presence as the Z4 M, the 3.0si has less sharply sculpted body kit and different alloy wheels. Its cabin has a different trim, too, with glossy black piano-effect wood, slightly softer, less bucket-like seats, and a larger, thinner-rimmed steering wheel (3.0si Sport models, from £32,925, add the M alloys, seats, steering wheel and suspension, though this seems somehow to miss the point).
More crucially, however, it offers a very different driving experience. Both models share the same six-speed manual transmission, but the clutch is altogether lighter and smoother in the 3.0si. It makes for easier stop-start progress and is less wearing on the left leg over long distances. And whereas the Z4 M has hydraulically-assisted power steering, tuned for maximum feedback, the 3.0si is considerably less physical to steer. It has the same Servotronic electrically-assisted set-up as the Z4 roadster; not the most communicative for racing or track day use, but requiring less effort and arm-wrestling during normal road use.
Most marked, though, is the difference in the suspension tunings. As with most BMWs, the 3.0si Coupe is tautly-sprung - and super-rigid in its structure - but it's much less of a boneshaker than the Z4 M. The M, even on relatively well-surfaced roads, is unforgiving and - after an hour or so - somewhat unrelenting. Sitting so low to the ground, it's a spine-jarrer.
