WHEN somebody's job involves driving scores of different vehicles every day, that person's verdict on a car is worth a mint.
And when that someone heaps praise on a car having driven it only for a few miles, you know it is something special.
Such is the case with the Jaguar XJ TDVl - in my opinion the finest Jaguar ever made.
The additional adulation came from a chauffeur who drove the car during a recent event where valet parking was the order of the day. As he returned the Jaguar he remarked how impressed he was, despite having driven only six miles behind the wheel.
"That is one of the best cars I have had the pleasure to drive recently," he proclaimed. "A three-litre is it?"
When I told him it was a diesel, he was amazed.
"That's incredible," he said. "It does not feel or sound anything of the like."
He's right in every way.
The diesel version of the XJ Sovereign saloon has every attribute of a luxury Jaguar - and that includes performance - but is capable of averaging 35mpg.
That is eight miles per gallon more than a 4.2-litre V8 petrol engined Jaguar and, more importantly for business users, it is the only XJ that is not rated at 35 per cent Benefit in Kind tax.
As a diesel its CO2 exhaust emissions are down to 214g/km, knocking the tax charge down to 29 per cent.
It all adds up to make this executive steed very appealing.
The 2.7-litre twin turbo V6 engine has been developed by Jaguar's parent, Ford, as a result of its diesel programme collaboration with French car group PSA - the makers of Peugeot and Citroen.
At the moment it is probably the finest diesel engine in the world. With 204bhp on tap and the benefits of the XJ's lightweight aluminium body it can accelerate from 0 to 62mph in 8.2 seconds and has a reported top speed of 141mph.
Ten years ago that would have been unthinkable with a diesel engine and in this Jaguar it creates a very special car.
Jaguar is all about the finest of qualities and all of these are apparent on the XJ diesel - not least the sound insulation which results in it being as quiet inside as any petrol-engined version.
Leather upholstery and wooden trim are of the highest calibre and the car is as smooth as silk to drive.
High tech features such as an electronic parking brake and touch-screen full colour display to control the navigation, communications and entertainment systems make this one of the great cars of our time.
Pound for pound this is the best value car Jaguar has created in its long and illustrious history. Why any British businessman or woman who puts status vehicles at the top of their list would want to look anywhere else I don't know.
They would be stupid to do so - just ask the chauffeur from the valet company.
FAST FACTS
Jaguar XJ6 TDVi Sovereign
Price: £49,995
Mechanical: 204bhp, 2,722cc, 6cyl diesel engine driving rear wheels via 6spd automatic gearbox
Max speed: 141mph
0-62mph: 8.2 secs
Combined mpg: 35
Insurance group: 17
CO2 emissions: 214g/km
BiK rating: 29%
Warranty: 3yrs/ unlimited mileage; 3yrs paint; 6yrs anti-rust