The entry-level 18i version has a 154bhp 2.0-litre four-cylinder engine. However, the 20i version of the same engine has useful extra power and is our pick of the range – it doesn’t need to be worked as hard and suits the Z4’s sporty character better. There’s a big price jump to the 28i version of the 2.0-litre motor, which delivers more power. If cost isn’t a concern you should also consider the six-cylinder 35i and 35is versions, which offer true performance car pace.
BMW Z4 ride comfort
Comfortable, as long as you avoid M Sport suspension
The Z4 rides surprisingly smoothly for a car with a sporting character – as long as you choose the right version, that is. Standard sDrive suspension is firm, but it controls body movement well and softens the blow of all but the worst bumps. You can specify this as a no-cost option for M Sport models – as standard they come with a firmer set-up that sharpens the handling slightly but is uncomfortably stiff.
Adaptive M Sport suspension is standard for the 35is and a cost option for M Sport models. This adjustable system allows the driver to choose varying levels of comfort or sportiness, or leave it in ‘auto’ mode and let the car decide. It’s a good compromise.
Bear in mind that the higher up the range you go the bigger the alloy wheels are, which add an increasingly unforgiving edge to the ride.
BMW Z4 handling
Fun, but not as rewarding as key rivals
The Z4 is enjoyable to drive, if not as much fun as you might expect a rear-wheel-drive roadster to be. It’s certainly not as engaging as Audi TT Roadster or Porsche Boxster.
Grip is excellent, but although it’s agile the Z4 isn’t as incisive on twisty roads as those rivals and the steering is short on feel and consistency.
Versions with stiffer M Sport suspension have slightly sharper handling but fidget too much over mid-corner bumps. Adaptive M Sport suspension – an option for all but the 35is models - allows you to choose varying degrees of chassis sportiness.
Every Z4 comes with Drive Performance Control, which lets you tailor the responses of the steering, throttle and stability control system according to different modes.
BMW Z4 refinement
Hard-top keeps out most noise
The Z4 has a folding metal roof (rather than a fabric hood), which means it’s quieter than most of its rivals. There’s less wind noise than in an Porsche Boxster, for example, and there isn't much buffeting in al fresco mode, either. A wind deflector that reduces turbulence even further is a cost option – it’s not expensive but it’s disappointing that BMW makes you pay extra for it.
A fair amount of road noise finds its way into the cabin at speed. Engine noise only intrudes when you want it to, which is exactly what you want from a roadster. It’s just a pity the four-cylinder engines aren’t more tuneful.
This entry-level 2.0-litre, four-cylinder petrol engine is more lively than the output of just 154bhp suggests, partly thanks to its smooth power delivery. However, there’s no penalty in fuel economy or CO2 emissions if you upgrade to the 20i, which provides the stronger performance that a sporty car like this deserves. A six-speed manual gearbox is standard; a very slick eight-speed conventional auto is an option.
This is our favourite engine in the Z4 range – it’s as efficient as the 18i (which is effectively a de-tuned version of this engine) so won’t cost too much in fuel and tax, but provides a bit more oomph. Strong right through the rev range, it’s a smooth performer, when paired with either the standard six-speed manual gearbox or the optional eight-speed auto.
Despite the name, this is in fact another derivation of BMW’s 2.0-litre four-cylinder petrol engine. It delivers rapid acceleration without any increase in fuel economy or CO2 emissions, officially at least. There’s quite a jump in price, however, so we think you’re better off with the 20i. Transmission options are a six-speed manual as standard, or a smooth eight-speed auto as an option.
This twin-turbo 3.0-litre six-cylinder engine combines silky-smooth power delivery with a terrific engine note and blistering performance. It’s not hard to see its appeal, although at this price level it pitches the Z4 against the outstanding Porsche Boxster. Running costs are pretty high, too, so we think a 20i makes more sense overall. A six-speed manual gearbox is standard; the automatic option is a seven-speed dual-clutch unit.
This is the fastest Z4, which used an even more powerful version of the 35i’s twin-turbo 3.0-litre six-cylinder engine, mated to a seven-speed semi-auto transmission. It’s brutally quick and turns the Z4 into a true performance car. It’s also expensive to buy and run – cheaper Z4s, in particular the 20i, make more sense all-round.