Until now, Porsche has preferred to keep the two-peas-in-a-pod similarity of its mid-engined roadster and coupé on a mostly unspoken basis.

The Boxster preceded the Cayman by almost a decade, during which sales of the original 986-generation Boxster helped turn the ailing manufacturer around and re-established a more affordable ‘recreational’ end to its sporting line-up.

It wasn’t until the development of the 986’s replacement at the turn of a new millennium that a mooted coupé version was brought to life – and although it featured the same engines and platform (not to mention 90% of the look), Porsche was careful to distinguish it from the 987 with its own curiously crocodilian name.

Now, with the introduction of a new and slightly contentious engine line-up, the blood relationship between the Cayman and Boxster has been made explicit: you’re chiefly buying a Porsche 718. The choice between open-top and hard-top isn’t substantially different from choosing between the standard 911 and its cabriolet variant.

News that the Cayman is at last the cheaper option of the two models is welcome. Yet from an enthusiast perspective, it does all go a little against the grain because the Cayman’s unequivocal triumph has been to lodge itself in our mind as Porsche’s optimum ‘driver’s car’ – distinct even from the 911 in its reasonably priced delivery of rounded sports car brilliance.

Dilution of that status is our chief concern, then. Which brings us to the big news of the 718 facelift: the flat four turbocharged engines that have proved highly capable yet uninspiring in the Boxster.

The choice is the same here as there: a 296bhp 2.0-litre unit and the larger 345bhp 2.5-litre motor that fills out the S model tested here.

Both engines are more powerful than the six-cylinder motors they replace.

The S, tantalisingly, is claimed by Porsche to be quicker than the God-like Cayman GT4.

But better? That’s the 718-dollar question. 

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