BMW’s range-topping Z4 roadster gets more grunt

BMW Australia has announced a power increase for the range-topping M40i variant of the brand’s open top Z4. The three-litre six-cylinder B58 engine sees an additional 35kW to bolster the headline figure, aligning it with other BMW ‘40i’ variants.

Thankfully the increase in power hasn’t brought an increase in price, BMW still sells the M40i for the same $124,900 ($135,214 driveaway).

Chasing Cars tested the 2019 Z4 M40i against the Toyota Supra – its brother from another home – but the roadster is really here to make a case against the open top Porsche Boxster and more conventional Audi TT.

When we drove the M40i we didn’t think it was exactly wanting for extra power, the 250kW and 500Nm from the B58 was more than enough to leave that car struggling for traction on pockmarked Sydney roads.

With the Australian release of the G20 340i xDrive and X3 M40i though it was only a matter of time before BMW upped the power figure to 285kW, though the 500Nm torque figure remains identical.

The chassis of the Z4 should handle the extra power well though, and the added grunt will propel the roadster from 0-100km/h in 4.1 seconds, four tenths faster than the outgoing M40i, that’s seriously impressive. 

Gear changing duties are taken care of by a brilliant ZF eight-speed automatic that provides smooth, quick shifts and importantly listens to the driver’s inputs, though no manual option is available.

Naturally, the Z4 M40i retains the brand’s 50:50 weight distribution calling card, as do other Z4 models.

The Z4’s exterior design is a polarising topic, the slightly buggy eyes are a turn-off for many, but from the rear three-quarter the shape of the roadster is nice and squat, it’s actually starting to grow on us. The details aren’t quite perfect, but the proportions are definitely there.

All importantly for a roadster the, roof still operates swiftly with the ability to open or close in 10 seconds at speeds up to 50km/h. 

The M40i sits at the top of the range with no Z4 M model likely to arrive, it receives AEB and adaptive cruise control, lane departure warning and blindspot monitoring, the latest generation iDrive system with voice recognition capabilities and wireless Apple CarPlay and Android Auto and a stiffer spring and damper package than sDrive models. 

The entry level sDrive 20i with its turbocharged four-cylinder engine produces identical outputs of 145kW/320Nm and is still available with a manual gearbox.

A mid-range sDrive 30i also remains with outputs of 190kW and 400Nm courtesy of a turbocharged four-cylinder engine. No manual is available, but we think this is a real sweet-spot in the Z4 range.

More power is rarely an unwelcome addition these days, but it won’t go any way to curing the aloof steering we found when we tested the Z4.

2020 Z4 Pricing

Z4 sDrive20i $84,900 ($93,209 driveaway)
Z4 sDrive30i $104,900 ($114,209 driveaway)
Z4 M40i $124,900 ($135,214 driveaway)