2019 BMW Z4 M40i Vs Porsche 718 Cayman Comparison Review
Frustratingly, things don鈥檛 always go to plan. If they did, we wouldn鈥檛 have the all-new BMW Z4 parked next to a Porsche 718 Cayman. And it also wouldn鈥檛 be endowed with the meagre 2.0-litre four-cylinder turbo. It is half-a-litre short on capacity and sans the essential topless ability we asked for when trying to secure a Boxster S for this comparison. Before pressing a starter button, this all seems a bit of a mismatch on paper. However, stats and figures can often mean little out on the open road and, ultimately, the body styles presented don鈥檛 tell the full story. Why would BMW allow us to bring a Porsche Boxster (that was the original aim, remember) to the launch of the new Z4? It鈥檚 certainly not as a favour. The red carpet was rolled out for our rival because BMW knew that the G29 Z4 has evolved into a proper sports car.
The original Z4 was an abomination from the Bangle design era, while the second generation was pretty, yet dynamically flawed with the retractable hardtop aimed squarely at the Mercedes-Benz SLK. Although the reality is that this line of ancestors might as well be from another family, because the third generation is a completely different animal. The boosted, 3.0-litre straight-six-powered M40i we have here blitzes the Nordschleife in 7:55.41sec, which is faster than the N55-powered M2 by a decent margin. Additionally, with 250kW and 500Nm, the claimed 0-100km/h time of 4.5sec is as plausible as it is impressive. Essentially, the Cayman is to the Boxster what the Toyota Supra is to the Z4. Also developed in Europe, the Supra breathes down the Z4鈥檚 neck much harder than is comfortable for the venerable German marque. Not surprisingly, the Cayman does the same thing to the Boxster. So unless you regularly lower the roof, the coupe should always be the driver-orientated choice over the roadster.
Well, that鈥檚 the theory, but in reality the Z4 is much closer to its Japanese counterpart than most would have predicted. 鈥淭he new Z4 is more puristic, dynamic and progressive than the outgoing model,鈥?says the project leader, Michael Wimbeck. 鈥淭here is no better roadster to explore empty B-roads early on Sunday morning than the new Z4.鈥?With that said, it鈥檚 time to get in the cars and drive. While the location of Lisbon is idyllic, the weather decides not to play ball. Dense sheets of rain persist as the seemingly drought-breaking precipitation transforms the parched surface into an ice rink. Grip becomes an entertaining illusion as both rear-drive steeds demand to be driven. Given half a chance the Z4 will fishtail away from the apex, while the Cayman offers a broader scope of understeer and oversteer. Still, the buffer zone between bravery and bad luck can be brutally narrow in these conditions.
As the rain mercifully clears and the strong winds dry the tarmac, the BMW starts pulling away from the Porsche in small, but quantifiable increments. Its main assets are a torquier and more powerful engine and the commendably rapid eight-speed automatic transmission. However, it weighs in excess of 1500kg, whereas 1365kg is listed for both the base Cayman and Boxster (the coupe still outperforms the drop-top for torsional rigidity and overall stiffness). The standard eight-speed auto makes it easy to climb the torque mountain, but it isn鈥檛 as quick or as sharp as the optional seven-speed PDK transmission in the Cayman. Without the dual-clutch 鈥檅ox, the Z4 would easily embarrass the Cayman. That controversial flat four, the smaller of the two, is better than its questionable reputation. Yet it relies on high revs to deliver and it doesn鈥檛 muster quite the same linear punch as a flat six - and it sounds more like an air-cooled Beetle on steroids than a detuned M1. The 220kW, mid-engined Porsche is blatantly entry-level instead of cream of the crop. For acoustics, the M40i has this comparison licked.