'We have had a number of people - mostly motoring journalists - phone to tell us we are mad,' admits Peugeot's PR director Andrew Didlick, surprised at the initial response to the company's plans to sell a diesel-powered version of the graceful 406 Coupe.
This negative reaction is largely down to long-held views that diesels are slow, unrefined and dirty and that they certainly have no place in a car as beautiful as the Pininfarina-styled Coupe.
But just as the technology itself is changing, so is public perception - aided, no doubt, by the forthcoming changes in benefit-in-kind taxation. It is just the hacks who are behind the times.
That said, Peugeot regards the 406 Coupe HDi as a toe-in-the-water exercise. The company could have taken the car in February when it was launched in Europe, but didn't feel that the time was yet right.
The time has come, however, and across Europe, the new diesel version is taking 55% of Coupe sales. That won't be the case in the UK, where diesels account for 'only' 30% of Peugeot sales, but confidence is clearly growing.
While UK Coupe sales are not huge - Peugeot sold 1,779 examples last year and less than 7,800 since sales started - a critically acclaimed diesel-powered version is likely to have a halo effect over the rest of the diesel range. It will also appeal to the more astute company car driver who wants a bit of style without having to pay a fortune for the privilege.
Creating the 406 Coupe HDi was hardly tricky, as all the elements were already in place. The Coupe has been around since 1997, and was mildly facelifted two years later.
Peugeot's 2.2-litre turbocharged HDi engine is more recent, but already sees service in the 406 saloon and estate models and in the 607 as well as in the C5 range from sister company Citroen.
It's a gem of an engine. Displacing 2,179cc, the turbocharged direct injection unit develops a petrol-like 139bhp and a most un-petrol-like 235lb-ft of torque. To put that in perspective, the 2.0-litre petrol version of the 406 Coupe has 135bhp and a mere 135lb-ft of torque.
These differences are reflected in the performance figures. The 2.0-litre petrol equivalent has a top speed of 126mph and takes 10.4 seconds to sprint from 0 - 62mph while the diesel tops 129mph and covers the standing start sprint in 10.9 seconds.
The diesel comes into its own on the move, where the in-gear acceleration times are noticeably quicker, and at the pumps. Peugeot claims the 406 HDi is some 30% more fuel efficient than the petrol version, and records 44.1mpg over the combined fuel cycle.
It is also far more efficient when it comes to your pay packet. Thanks in part to Peugeot's innovative FAP particulate filter, the diesel produces just 168g/km of CO2 - 15% less than the petrol version - which gives it a BIK percentage figure of 18%, the lowest possible for a diesel.
The days of a diesel being the poor relation to a petrol car in terms of equipment are also long gone. The HDI matches the equipment levels of the petrol version exactly. The entry level S version has air conditioning, twin front airbags, anti-lock brakes, alloy wheels and a multi-disc CD player as standard, while the plusher SE adds leather sports seats, side airbags, satellite navigation and cruise control. And when it comes to car park prestige, the best news of all is that there are no badges to identify its diesel status.
Only on start up, and especially when the engine is cold, will the 406 Coupe HDi passenger be aware the car is diesel-powered. Otherwise - and provided the driver keeps away from the 5,000rpm red line - the car is easily as refined as the equivalent petrol version.
Only as the needle gets close to the rev limit does it lose some of its finesse, but such is the broad spread of torque that it should never be necessary to go above 4,000rpm. In fact, on the move all the revs you'll need lie between 1,500 to 3,750rpm - at the lower figure the turbo starts to make its presence felt while towards 4,000rpm, performance starts to drop off as noise increases. At motorway cruising speeds the engine is virtually ticking over, yet there is always ample power on tap should the need arise.
Although the power and performance figures for the diesel are broadly similar to those of the petrol, the HDi always feels the livelier of the two. And quicker on a long run as with 40mpg plus on the cards, the diesel driver can cover much greater distances before having to refuel.
In all other respects, the Coupe HDi is as other 406 Coupes. The well-weighted power steering gives reasonable feedback and the car is as entertaining to drive as ever. The timelessly elegant shape remains surprisingly practical. The boot is big enough for several sets of golf clubs, while the interior will hold four adults in some comfort. Getting to the rear seats requires a certain agility, but once installed, there is sufficient leg and head room for most.
Oddment space is good, too, with a deep-lidded box on the rear parcel shelf and a neat storage compartment between the two individual rear seats.
The only downside is the cheap-looking black plastic used for the interior. Not only is it at odds with the svelte exterior, the dashboard layout is starting to show its age. Shame there wasn't enough in the kitty to let Pininfarina have a go at the inside as well.
Perhaps the only eyebrow-raising element to the entire package is the list price - at £22,295 for the S and £24,995 for the SE, the new HDi Coupes are a cool £2,300 more than the equivalent petrol versions.
So, is the concept of a diesel coupe an astute move or a complete contradiction? In the eyes of a few journalists still wedded to the view that only petrol power can provide the necessary thrills, it is undoubtedly a disaster. But, price premium aside, the 406 Coupe HDi has it all - performance, refinement, economy and that genuine star quality that goes hand-in-hand with virtually everything that Pininfarina produces. On balance, then, a very shrewd move.