Merc’s SLK roadster now holds greater appeal to business car drivers as it can be specified with the firm’s 2.1-litre diesel engine.

In terms of efficiency, CO2 of 132g/km and a claimed 56.5mpg put it ahead of its chief rival, the drop-top version of the Audi TT, as BMW?is yet to launch a diesel version of the Z4. Although the diesel might lack the enthusiastic appeal of petrol that traditionally dominates this segment, it more than makes up for this with heaps of mid-range power.

The Merc errs towards comfort over sport, not least as it comes with a seven-speed auto gearbox. A smooth ride adds to its easygoing nature.

The SLK CDI makes a decent case with its starting P11D price of £32,080 – though that’s getting on for £2000 above the admittedly fabric-roofed TT, The AMG model tested here costs £36,080, compared with the front-wheel drive TT TDI S-line’s £32,285.

Two seats and a folding hard-top mean practicality is limited, but the 335-litre boot (roof up) is class-leading, and the cabin isn’t short of space.

Creature comforts are abundant on the options list, but they do cost. Our car was fitted with Mercedes‘ Comand media system comprising satnav, DAB radio and other infotainment features at a cost of £1995. It’s easy to creep over the £40,000 mark.

Fit and finish in the cabin are of the highest quality, and road and wind noise are impressively quiet for a convertible. The only let down as far as refinement is concerned is the diesel engine, which emits a clatter from idle.

Emotional appeal remains the Merc’s strongest suit, even with its clean and frugal engine, but it’s easily the most sensible choice for business car drivers in the premium convertible sector.

Mercedes-Benz SLK 250 CDI BE AMG
P11D price £36,080
Model price range £30,480-£54,950
Residual value 44.0%
Depreciation £19,855
Fuel £7114
SMR £3114
VED £415
National Insurance £3137
Cost per mile 73.8p
Fuel consumption 56.4mpg
CO2 (tax) 132g/km (%)
BIK 20/40%
per month
£120/£240
Service interval 16,000 miles
Insurance (1-50) group 20
Warranty 3yrs/unlimited mls
Boot space 225/335 litres
Engine size/power 2143cc/204hp
Top speed/0-62mph 151mph/6.7secs
On sale February 2012
Score 8/10
Verdict Diesel engine makes it
the best premium, two-seat
convertible for fleets