BMW Z4 roadster review: Game-changer ready to chase down Porsche

This new BMW Z4 roadster almost didn’t exist because BMW’s bean counters weren’t sure there was enough demand for an open-topped sports car.

Everyone wants SUVs and crossovers. And knocking up a car platform from scratch costs hundreds of millions, so BMW struck a deal with Toyota – the Z4 gets a Toyota-developed platform while Toyota’s new Supra carries a BMW engine and running gear.

Happy days.

This Z4 is a very different car to the one it replaces. For starters it has a proper fabric roof and not a folding hard top. This knocks 50kg off the new car’s weight while allowing a bigger boot.

I think a cloth roof looks better. Metal folding roofs were developed because they sealed better and made for a quieter drive, but nowadays fabric roofs are so well made there’s barely any advantage in using metal.

Plush interior of the car developed to take on the Porsche
(Image: newspress.co.uk)

The main decision when buying a Z4 is whether you want the 2.0-litre four-cylinder engine which goes in the Z4 sDrive 20i (197bhp) and in the sDrive 30i (258bhp), or the six-cylinder, 3.0-litre unit in the M40i we’re testing here.

But we’ve driven the 20i too – and that’s an impressive car in its own right.

The M40i’s straight-six produces 340bhp – more than enough power and a very nice sound to go with it, although if you’re old school and like manual gearboxes, you’re out of luck.

In the old Z4 you used to sit a long way back, almost on the back axle. In the new one you’re further forward.

In front of you is a chunky steering wheel. Really chunky.

Where does it say in the ancient scriptures of sports car design that a steering wheel has to be as fat as a Cumberland sausage for it to be suitable?

BMW Z4 roadster is yours for a shade under £50,000
(Image: newspress.co.uk)

Behind the wheel are digital instruments that aren’t at all clear to read. What’s wrong with an old-fashioned round dial for a rev counter? You can order a head-up display and I’d tick that box.

The choice between a Porsche Boxster and BMW Z4 used to be pretty straightforward – if you wanted a proper sports car you bought the Porsche. Now it’s not so simple because Porsche put a really poor flat-four turbo engine into the car in place of the lovely six-cylinder engine that used to live there.

By comparison the Z4 M40i’s engine is in a different league. The Porsche is still the better and more sporty car to drive but BMW has closed the gap.

The Z4 has variable mode suspension that gives the car a comfortable ride when you’re cruising but allows you to sharpen up the body control, steering and throttle response when you find a more exciting road.

You don’t get the lovely noise or the power of the six-cylinder engine in the cheaper Z4s but you do get a car that is actually nicer to drive because it feels well balanced and steers better. The 20i and 30i are also lighter with the four-cylinder engine.

At £49,065 the M40i is an expensive car and that’s without any options fitted. It will be easy to take the car to £55k. The four-cylinder cars, even the 20i which we also drove, are more than quick enough and at £36,995 much more affordable.

There are drivers who will want the macho appeal of the M40i badge but those just interested in a well-balanced sports car will find the sDrive 20i will do the job.

And if you want a simple roadster with a folding cloth top and adequate performance you could always save a bundle more money and buy an MX-5.

But that’s a Mazda, not a BMW.