Costs & verdict
Everyday costs, plus how reliable and safe it is
The Z4 roughly follows the pricing structure of its rivals. The entry-level 20i and 30i are priced similarly to equivalent versions of the Audi TT Roadster, while the M40i is nearer to the more powerful Porsche Boxster and Audi TT RS. Resale values are predicted to be similar to the TT's, but not as strong as the Boxster's, while insurance and servicing costs are all competitive.
If you're a company car user with benefit-in-kind tax on your mind, you’ll be pleased by how the Z4 20i and 30i’s official CO2 emissions are comparatively low, while those that pay their own way at the pumps will find the fuel consumption relatively palatable.
Choose the 20i or 30i and you’ll have a choice of two trim levels: Sport and M Sport. The former comes with a decent amount of toys, including 18in alloy wheels, power-folding door mirrors, dual-zone climate control, heated front seats and leather seat trim. We'd stick with that, because the latter adds more aggressive styling details in the main.
The M40i is based on the M Sport but adds the bespoke sporty tech, brakes and electric seats we discussed earlier, plus 19in alloy wheels.
We can’t say for sure how reliable the Z4 will be, because it's too new to be measured. However, what we do know is that BMW finished a disappointing 21st out of 31 manufacturers in our 2019 What Car? Reliability Survey, below Audi but above Porsche.
In terms of crash protection, the Z4 not only achieved a maximum five-star rating from Euro NCAP, but it also got a special mention in NCAP’s end of year awards for setting a “new safety benchmark for the segment”. For reference, its closest rival, the Audi TT, only achieved four stars when it was tested back in 2015.
It also comes packed with safety kit like 'front collision warning' with automatic emergency braking and a lane departure warning system. You can also add a Driving Assistant Package for more driver aids, including a clever bit of tech, which can detect traffic crossing behind you as you’re reversing out onto a road, lane-keeping assistance, which steers you back into line, traffic sign recognition, and, as a bonus, adaptive cruise control.

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