The first turbo works at low revs, while the second smaller turbo comes on stream as the rpm needle sweeps past the half way point. In the BMW it’s the other way around – the small turbo gets to work first and then the bigger one.

Jaguar is making a lot of noise about this point. Its own research confirmed 95 per cent of people have a driving style which demands maximum torque below 4,000rpm.

So Jaguar has obsessively engineered the engine to sing as soon as you pull away or drive out of a sharp bend.

It’s better in every way than its 2.7-litre predecessor – itself an acclaimed motor – and yes, it ends the domination of BMW’s diesel too.

The engine note isn’t as snarly and sporting as it is in a BMW 535d, but it’s more refined all the time.

Listen very carefully and you can hear the signature sound of its V6 layout, and some interesting turbo whistles and hisses.

The huge accelerative punch and effortless speed in any gear when you put your foot down has to be felt to be believed.

Take into account its combined fuel economy of 42mpg and incredibly low emissions of 179g/km and it’s a hard package to criticise.

You will also be able to get the same engine in de-tuned spec, with 240bhp and 369lb/ft of pulling power. But, this drop in power doesn’t bring an increase in fuel efficiency or a reduction in emissions.

Awesome soundtrack

Which brings us on to the all-new 5-litre V8. Put simply, it has a soundtrack and driveability to die for.

If you want an XF purely for its feel-good factor on high days and holidays look no further.

Compared with its supercharged 4.2-litre predecessor, power is 385bhp (29 per cent increase) and pulling power is 380lb/ft (25.3 per cent increase).

Its delivery is incredibly smooth, giving you so many options as a driver. Change up through the gears at low revs and you waft almost silently at a very decent rate of knots.

Put it into sport mode or pull back on the left gearshift paddle and the car changes character, revving to a wonderful crescendo which evokes memories of Le Mans racers.

If anything we wish the engine was slightly louder inside the cabin, but this wouldn’t be the Jaguar way.

For most the 5-litre V8 won’t be worth the big penalty at the pumps (combined fuel economy is 25.4mpg, emissions of 264g/km) when compared with the excellent diesel.

But those who are willing to pay the premium and choose this high-tech V8 certainly won’t be disappointed.

Great to drive

As the old saying goes - power is nothing without control. So it’s handy the XF has a chassis which is seriously hard to fault. The effort Jaguar has put into its development is clear to anyone who drives the car.

You don’t have to be a wizard behind the wheel – it makes the whole experience effortless. Almost too easy when you reach a town and need to concentrate on bringing your speed down to match the legal limit.

Smooth steering with excellent precision (if a bit lacking in actual feel) instils confidence in the hugely trustworthy way the car turns into a corner and grips time after time.

Even if you do test the tyres limit of grip (which is hard) the DSC sorts out the car subtly and quickly. Information from the XF’s wheels is processed 500 times each second by the onboard computer.

The gearbox also deserves a special mention, because it’s one of the best we’ve ever sampled. Its six ratios are perfectly matched to the car’s engine, keeping it at low revs most of the time.

Even high-speed progress is relaxed in the upper gears, giving you a real sense you can cross whole continents with ease.

Leave the steering wheel mounted gearshift paddles alone and the shifts are so smooth they are almost imperceptible. Turn the drive selector to sport and each gear is held for longer.

Pull back on a shifter though, and the real fun begins. Downshift and there is a flurry of revs and pop from the exhaust in an instant.

Commands are instantly met (unless a downshift would take revs far too high, in which case the car waits until your speed has dropped) in a way which only the best dual-clutch gearboxes can compete with.

While the mechanical changes are significant, the exterior ones are not. But we don’t mind – the XF was already a lovely car to look at and it’s still fresh.

The door mirrors have been re-styled and now cut through the air more efficiently and sport enhanced LED side repeaters.

Best in class

There are four new colours to choose from and three new wheel designs.

We loved the Jaguar XF when we first drove it. Now, it’s really a great car.

Is it a return to glory for Jaguar? Certainly. It always had the Audi A6, Mercedes E-Class, Lexus GS and BMW 5 Series well and truly licked in the looks and character department.

Now it shows them the road home dynamically too.

Video: Watch the Jaguar XFR hit 225mph on the Bonneville Salt Flats in Utah