First look: BMW gives Z4 the M treatment

IT may well be a very exclusive club but there’s a new member knocking at the door.

BMW has confirmed that it will add the much-anticipated M Roadster to its refreshed Z4 line-up early next year.

The sleek M Roadster will go head-to-head with the Mercedes SLK AMG55, Audi S4 cabriolet and the Porsche Boxster 3.2 S, which means six-figure prices in an atmosphere of rarefied high-performance rivalry.

The powerful two-seater will share the same highly respected 3.2-litre straight-six powerhouse previously seen in the E46 BMW M3 coupe and convertible.

In the Roadster, BMW claims the M3 engine rockets the car to 100km/h in five seconds and on to an electronically limited top speed of 250km/h.

The 3.2-litre six develops 252kW at 7900 rpm and 365Nm at 4900rpm, and revs as high as 8000rpm.

It is mated to a six-speed manual transmission with a short-throw sports gearshift.

To ensure the M Roadster doesn’t become a handful, the speed-sensitive variable M differential lock, borrowed from the M3 Coupe, is standard. It delivers superior driving stability and optimum traction, especially when accelerating out of corners.

Attention has also been paid to the car’s braking system, which is the motorsport-developed BMW M floating compound high-performance brake system used on the BMW M3 CSL.

Visually the Z4 gains new front and rear bumpers and revised tail-lights while the slinky profile remains largely unchanged.

With its long bonnet, set-back cabin and longitudinally mounted straight-six engine driving the rear wheels, the Z4’s core attributes have not been altered.

The double-spoke 18-inch alloys are exclusive to the M Roadster, while the rear view is dominated by the M trademark quad-exhausts.

Inside, the car features black-faced BMW M instruments with white numerals and red needles and more upmarket trim and detailing.

The rev counter follows M practice having yellow warm-up warning lights, illuminated while the engine oil comes up to temperature.

The steering wheel, gearshift knob and door sills are specific M items, while the air conditioning, air vent registers and interior door handles are finished in pearl-gloss chrome.

The M Roadster will be the third model in the Z4 lineup.

The revised 2.5si and 3.0si models gain the latest Valvetronic-equipped double-Vanos magnesium-alloy straight-six engines.

The 3.0si delivers 195kW at 6600rpm with 315Nm available between 2500rpm and 4000 rpm while the 160kW 2.5si offers 250Nm between 2900rpm and 4250rpm.

The punchy 3.0si hits 100km/h in 5.7 seconds and has an electronically limited top speed of 250km/h. Fuel consumption in the combined EU cycle is just 8.6L100 km.

The 2.5si is not to shabby either, hitting 100 km/h in 6.5 seconds and pushing on to a top speed of 240km/h. Fuel consumption is just 8.4Ll/100km.

All models will offer a six-speed manual as standard with a new Sport Automatic available to 2.5si and 3.0si buyers, complete with steering-wheel mounted shift paddles.