The anti-diesels guffawed, but they were spectacularly wrong. A trend kicked off by BMW in the drop-top Three Series was picked up by Audi in its A4 cabrio range. After just three years, diesel convertibles are chomping into a third of the cabrio sales pie.
So you can understand Volvo's eagerness to join the trend. This spring, it unveiled a folding hardtop C70 in petrol versions, but from September you can park this alternative at the black pump.
The 'D5' badge sounds dull, but this car aims to offer maximum oomph for minimum ouch, thanks to a 178bhp 2.5-litre turbocharged unit that reaches 62mph in a fairly respectable 8.8 seconds and pledges to get you about on an average of 38.7mpg. Against the 2.4-litre and top-end 2.5-litre petrol alternatives, this is the slowest choice, but neither petrol model goes past 32mpg overall, so the diesel's weekly savings sound impressive.
Look closer though. At ¯¿½29,420 for the cheapest 'port' version, the D5 is ¯¿½3,195 pricier than the 2.4-litre petrol. So petrol choosers effectively get more than 21,000 miles of free motoring, while from the D5 has to notch 64,000 miles before that premium begins to return a benefit. To its credit, at 193g of carbon per kilometre, the D5 has the range's cleanest exhaust.
And for the money, you get two cars in one. Roof up, this is a traditional coupe, with handsome lines and none of the security risks association with a soft-top. The C70 is wider, longer and taller than a BMW or Audi cabriolet but is very balanced and, like any Volvo, feels as suited for maritime expeditions as road work.
Inside, the aura is more subdued Swede than flashy playmate - good detailing and solid craftsmanship, but all just a tad bland. Rear-seat leg room is likely to be cramped for two adults, albeit fine for children.
Equipment, as you might expect for the dosh, is lavish. The Sport has air con, cruise control, steering-mounted audio buttons and a postcode-rocking six-speaker CD and radio system. You also get a leather steering wheel and gear knob and finely crafted aluminium panels on the dash and gear console, but you'll need to shift up to SE grade (¯¿½30,670) if you want full leather and an electric driving seat. The SE Lux (¯¿½33,170) showcases an ASBO-attracting 910-watt music system. Safety-wise, all C70s have a super-fast pop-up hoop system which is triggered to protect against injuries in a roll-over, as well as curtain airbags tucked inside the doors.
The C70's most exciting trick is performed when stationary. Press the roof button and a complex system of electric and hydraulic pumps, pulleys and twiddly bits of cord whirr into action for 30 seconds of eye-widening spectacle. To try and boost cabin and boot space, Volvo insisted on a Heath Robinson tribute that concertinas into three sections, in contrast to the industry-standard two. When down, bootspace is halved and larger items are irretrievable until the top's back up.
Roof down, you'll need some loud music to drown the engine's initial taxi-cab clatter. Warmed-up though, it's as quiet as most petrols, with only an occasional 'swoosh' from the turbo when overtaking to remind you it's a diesel. Handling on corners is surprisingly good with no real flex from the body to spoil the ride.
Despite the easy dollop of low-down power for overtaking, a slightly numb steering helps make this C70 feel a bit disconnected, while the auto-only specification puts pay to any slick gearchanges. Against the comparative edge of Audi's new A4 3.0TDI Cabriolet, the C70 is distinctly fuzzy. And if you opted for Audi's 2.0TDI alternative, you'd enjoy the clearer boon of a car that achieves 43.5mpg overall, even if it is slightly slower.
Despite the dodgy economics, Volvo is confident the C70 D5 will strike its target: it expects to sell 1,400 in the coming year. But parked alongside its cheaper and more communicative petrol stablemate, you can't help feeling the D stands for Could Do Better.
Tiscali verdict: A comfy doss for maximum dosh: Volvo's lid-free diesel 6/10
