First drive: M Roadster returns with a vengeance

BMW’s born-again M Roadster has arrived Down Under this month as part of a facelifted Z4 convertible range, and the good news is the Munich maker’s latest M model has all the attitude of its feisty 1997 Z3-based predecessor - but commands a significantly lower $129,500 sticker price.

The keen pricetag was revealed at February’s Melbourne International Motor Show, where the Z4 M Roadster made its Australian debut as a preview to the return of M power in a convertible BMW for the first time in more than five years.

BMW said the return of its M Roadster was in response to customer demand and just 30 examples would be made available in Australia this year from April - four months ahead of the Z4 M coupe’s arrival here as the spiritual successor to the even more exclusive Z3-based M coupe, known affectionately as BMW’s "munster mobile".

Powered by the same legendary 3.2-litre inline six that powers the 1500 E46 M3 coupes sold here since 2001 (a surprising 80 per cent of which are fitted with BMW’s SMG sequential manual transmission), the Z4 M convertible delivers 252kW at a revvy 7900rpm, along with 365Nm of torque at 4900rpm.

An "Engine Oscars" winner for each of the five years it has been available, the six-cylinder M engine easily breaks the 100hp mark for specific power output by offering 77.6kW per litre. Along with an 8000rpm redline, it offers 80 per cent of its peak torque from 2000rpm. However, like the forthcoming Z4 M coupe, the manual-only M roadster is not available with SMG as BMW’s clutchless manual gearbox is not compatible with the Z4’s narrow transmission tunnel.

Weighing 85kg less than the M3, the Z4 M Roadster blasts to 100km/h two-tenths quicker in a claimed five seconds flat - making it quicker around the Nurburgring than the M3 and the best-accelerating current M model behind the V10-powered M5 super-sedan.

As with its Z3 forebear, the M roadster’s chassis has been tweaked to handle the extra performance, with the Z4’s spring-strut front and 3 Series-based multi-link rear suspensions riding 10mm lower and featuring new lower front control arms and more negative camber than in the 2.5si/3.0si.

However, the biggest modification to the Z4 donor chassis is the deletion of the convertible’s controversial electric power steering system, which makes way for a traditional hydraulic power-assisted rack-and-pinion system.

Just as no M cars come with BMW’s active (variable ratio) steering system, BMW claims a conventional steering system "is more appropriate" for the Z4 M Roadster. BMW also says the Z4 M Roadster goes without the lesser Z4 variants’ run-flat tyres because they are heavier.

Cross-drilled M brakes derived from the M3 competition package are fitted, as is the M3’s variable M rear differential.

A specific front bumper with an even larger front airdam and black upper and lower air intakes have been fitted, while the M’s similarly aggressive rear bumper features a diffuser, quad exhaust outlets and M badging. Unique 18-inch M wheels round out the external styling differentiation.

In addition to the facelifted Z4 3.0si’s standard equipment, the M offers an alarm, park distance control, Xenon headlights, satellite navigation with TV, Bluetooth compatibility, Nappa leather trim and metallic paint.