I THINK I might have just driven the best car in the world. For someone who drives upwards of 200 different cars a year, this is perhaps a bold claim to make, but I have good reason for making it.

The car in question is the Volkswagen Phaeton, in long-wheelbase V10 TDI form, and before some of you start sniggering, we’ll set aside the running costs issue for now and look as the car as a piece of engineering.

As a new entrant to the luxury sector and with a long heritage in the mass market, the Phaeton must have been engineered to a higher standard than any other luxury car. As an all-new model, Volkswagen could not afford to be criticised for not matching up to rivals, so it would have ensured at matched or bettered them in all key areas.

Let’s take the air conditioning system. This has been designed for draught-free ventilation with no unpleasant blasts of cold air, but could be no less effective than the climate control systems in an Audi A8, BMW 7-series, Mercedes-Benz S-class, Jaguar XJ or Range Rover.

In fact Volkswagen says the system is capable of maintaining a steady interior temperature of 22 degrees Celsius at a constant speed of 186mph in an ambient temperature of 50 degrees.

It is also a four-zone system, catering to the individual temperature requirements of each passenger.

All components are designed for a maximum speed of 186mph. Aluminium is used in the doors, boot and bonnet, while the front wings are plastic. The Phaeton also features laminated side glass to keep noise levels to a minimum. The long-wheelbase model is 120mm longer (five inches) than the standard car and that translates directly into extra rear legroom.

Every Phaeton has continuous damping control (CDC) air suspension, 4MOTION all-wheel drive, sophisticated stability and braking systems and a six-CD autochanger, while our test car had 18-way adjustable front seats with heating, air conditioning with a massage function and many more items you didn’t realise you needed.

Tick the boxes on a long-wheelbase Audi A8 4.0 TDI quattro to bring it up to the same level and you part with an extra £5,600 or so.

And if you think that you might need to get out the leather-bound driver’s manual and spend an evening thumbing through the pages, you can bring up pages electronically on the central information screen.

The optional tyre pressure monitor (£395) not only gives you the reading of the four wheels in use, but also the spare tucked away in the boot.

The Phaeton also looks the part, combining elegance and a sense of purpose better perhaps than any other luxury saloon, while the cabin materials are top notch.

The Phaeton’s 5.0 V10 TDI is the most powerful diesel engine in production – with twin turbos it produces 313bhp and 553lb-ft. Not even Audi’s V8 4.0 TDI in the A8 can compete for brute force at 274bhp and 479lb-ft, although the A8 being considerably lighter through its aluminium construction accelerates a little faster.

Despite using pumpe duse technology instead of the generally more refined common rail systems, engine noise is muted inside the cabin at all times. Performance is so brisk you really can’t believe this Phaeton weighs two and a half tonnes and with the dampers set to sport and the reassurance of the extra traction afforded by the 4MOTION system, it can be driven with some enthusiasm.

A masterpiece of engineering, then.

But let’s talk money. This version of the Phaeton costs just over £60,000 and we have already mentioned it beats the top diesel Audi A8 on spec. The feeble six-cylinder diesels available in this class simply cannot compete, with the sector best of 225bhp in the Audi A8 3.0 TDI and 369lb-ft in the BMW 730d and Mercedes-Benz S320 CDI. Instead, the V10 Phaeton should be looked at in relation to petrol luxury cars and its 24.8mpg on the combined cycle is competitive.

Perhaps a 5.0-litre petrol car such as the Mercedes-Benz S500 L is a more realistic sparring partner.

It achieves 24.8mpg on the combined cycle for the seven-speed automatic version, is marginally faster from 0-62mph and could cost about £68,000 on the road to compare spec-for-spec, although the Merc does have standard sat-nav and PRESAFE, but no four-wheel drive.

The S500 L would lose about £44,000 in depreciation over three years/60,000 miles, according to CAP Monitor, compared with the Phaeton’s £43,000.

You can opt for a fixed cost servicing package for £500 on the Phaeton which would keep tight control over SMR costs, so the Phaeton needn’t be any more expensive than its rivals when comparing like for like.

The best car in the world? This could have been the design brief for the Phaeton at the start of development, but the title could be argued over for hours. However, as luxury saloons go, I believe it offers the most complete package.

Model: Volkswagen Phaeton 5.0 V10 TDI 4MOTION LWB
Engine (cc): 4,921
Max power (bhp/rpm): 313/3,750
Max torque (lb-ft/rpm): 553/2,000
Max speed (mph): 155
0-62mph (sec): 6.9
Fuel consumption (mpg): 24.8
CO2 emissions (g/km): 308
Fuel tank capacity (l/gal): 90/19.8
CAP RV (three years/60,000): £17,350/29%
Typical contract hire rate: £1,202 a month
Price (OTR): £60,375