AN epic journey of more than 2,000 miles from sunny Gibraltar back to rain-lashed Scotland in just three days with two overnight stops was guaranteed to put BMW's latest 5 Series to the test.

My verdict after the long trek is that this seventh generation 5 is the best executive express on the market by a considerable margin.

The 5 Series has been developed over the past 40 years and it just keeps getting better and better.

This latest version is a technical masterpiece, more refined than ever and still great to drive.

BMW have crammed this new car with technology making it even more connected and advanced than the larger and more expensive 7 Series flagship.

In addition the German car maker has managed to shave over 100kg off its weight despite the car being slightly larger than its predecessor.

And changes to the chassis have made sure that it remains the best driver's car in its class and it feels every bit as agile as the smaller 3 Series.

The 5 is still BMW's global best seller and prices start from £36,025. There is a wide choice of petrol and diesel engines with a plug-in hybrid model coming soon.

For my journey back to the UK I was paired with a 530d xDrive M Sport saloon costing £49,130 but the car was packed with additional equipment taking the final cost to an eye-watering £66,150.

BMW has taken no risks with the design of the new car and it is more about evolution rather than revolution but it is still handsome and there are some neat new touches.

From a distance you won't be able to spot a huge difference over the old car but the newcomer is superbly proportioned and looks the part.

The distinctive new LED headlamps now flow into the traditional double kidney grille and there are additional curves and creases on the flanks which help to disguise its bulk and also reduce the car's drag coefficient to as little as 0.22Cd on some models.

The kidney grille now takes an active part in making the car more efficient by opening its louvres only when cooling air is required - optimising aerodynamic efficiency.

Most buyers in the UK will opt for the M Sport which adds deeper front and rear bumpers, side skirts and larger 19-inch alloys to give the 5 a racy appeal.

Step inside the cabin and you will find exactly what you would expect - a super cockpit tailored to the driver - with first class materials, quality finishes and excellent build quality.

There is also more room inside this new model with extra headroom and more legroom in the rear. There are numerous storage areas inside and boot space has been increased to 530 litres.

The leather sports seats which are standard on the M Sport offer great comfort and are fully electrically adjustable. Once you have selected your driving position you can also choose to heat them and operate the massage function - which proved to be a welcome feature during my 2,000 mile dash.

Most cars in the range cost £3,000 more than the models they replace but BMW says that on average they contain £4,300 worth of additional equipment making them good value for money.

Packed with high tech features including Gesture Control for key functions like navigation, telephone and entertainment, you can also opt to use the traditional iDrive Controller, use voice commands or simply touch the commands on the 10.25-inch colour touchscreen.

A new message centre enables you to read all incoming SMS messages, e-mails and information about the car. The new car also has the best head-up display I have encountered which lets you have all the info you require without taking your eyes off the road. It also has its own Wi-Fi.

You won't get tired of driving this car but if you do it is perfectly able to drive and even park itself on its own - thanks to a bank of standard and optional driver assistance technologies.

With the heavily reworked 3.0-litre six-cylinder diesel under the bonnet the twin turbo produces 261bhp and a fantastic 620Nm of torque available from just 2,000 rpm.

This enables the 5 to sprint to 62mph in just 5.4 seconds before going on to a governed top speed of 155mph. It proved to be extremely smooth and quiet and combined with the eight-speed automatic transmission it was a joy to drive.

It burned up the miles on deserted Spanish motorways with ease and cruised at high speed with very low revs. There was little wind or road noise in the cabin and the power made overtaking easy.

On the second day we rocketed up through France on motorways that were just as quiet but astonishingly expensive and avoided going anywhere near Paris.

The car was fitted with BMW's xDrive all-wheel-drive system which proved to be a bonus when we hit wild windy and extremely wet conditions on the last 200 miles of our journey. xDrive is a £2,000 option on most models and a substantial amount of UK customers will choose it.

Even travelling at high speeds we averaged a superb 46mpg and BMW claim a combined figure of 53.3mpg. The official CO2 figure is 138g/km.

The grip was superb and the steering razor sharp while the optional adaptive dampers took all kinds of bumps in their stride.

The driver can also select from various driving modes depending on mood and I can't think of a car that would be any better for such a long journey.

BMW say they expect the new 5 Series to achieve 18,000 sales in the UK in its first full year and the lucky customers who order them will not have wasted their cash or rental money.