The Orient Express travels 1,400 miles across Europe from Paris to Istanbul once a year on the trip of a lifetime. It follows the original route mapped long before the very first Bentley was built 100 years ago. Well-heeled travellers would board at Gare de l’Est and luxuriate in Pullman carriages, with waiters catering to their every need. Their berths featured intricate wooden panelling, leather armchairs and the finest champagne on ice. The Express captured the imagination so comprehensively that it became the subject of countless stories – most famously Murder On the Orient Express, by Agatha Christie.

The Speed, the latest version of the Bentley Bentayga, is just as thrilling. The Crewe-built people carrier has a top speed of 190mph – that’s 0.5 mph faster than the latest Lamborghini Urus. As you might expect in a Bentley, the Speed features the best of everything. Hard-finished wood veneers, carbon-fibre trim and the finest hide seats adorn a sumptuous cabin. A solid gold, diamond encrusted Breitling clock can be yours as a £160,000 option too. Powered by a six-litre petrol engine, the Speed hits 60mph from standstill in just 3.9 seconds. The twin turbo W12 has been upgraded to 626bhp and shaves 0.2 seconds off the standard Bentayga 0-62mph dash. The exhausts are snarlier, the suspension firmer and this is the only Bentayga offered with sporty Alcantara trim – although luxury leather hide is available if you prefer.

My travel plan is to leave Paris and follow a high-speed road route to Istanbul, the bridge between Europe and Asia. While the train journeys via Vienna, Budapest and Bucharest, I’m driving to Strasbourg, Salzburg, then south to Belgrade and Sofia, before a final push to Turkey – although as it turns out, I won’t make the final destination by road. As I leave the French capital, even cool Parisians can’t resist a peek at Bentley’s £182,000-worth of motorised luxury. It could be the vibrant orange paintwork, but the Bentayga’s robust styling isn’t always well received. Finding a way out of the city centre from the newly restored Hotel Grand Powers in the 8th arrondissement and onto the Périphérique ring road involves countless pedestrian selfies – plus a paparazzi-style entourage on scooters. The A4 east to Strasbourg then, is a welcome relief. It’s a chance for the Bentley to do what it does best – stretch its legs and cruise in a straight line for mile after mile. I’m averaging just over 20mpg, not bad for 2.4 tons of handcrafted motor car that barely makes a whisper.

Strasbourg’s 2,000-year-old city centre wasn’t built for cars. The cobbled streets of the old town are sealed off to traffic and the city’s rich architectural heritage is jaw-droppingly beautiful. To avoid the tourist-packed streets, stay at Hôtel Les Haras, a contemporary conversion of the former national stud farm within walking distance. Salzburg is a nine-hour drive through the Alpine borderlands of Switzerland and Germany, but the Bentley munches up vast distances with consummate ease. Only fuel consumption suffers as the roads become more interesting across the mountains. Expect no more than 17mpg on an enthusiastic drive.

The Bentayga corners better than you might expect – for an SUV it’s almost nimble. The steering tightens up at speed and it starts to feel like a proper supercar. The Bentley is quick, too. Last summer a Speed broke the production car record at the Pikes Peak International Hill Climb in America.

Salzburg was designed for horses and carriages, and, like Strasbourg, is no place for a car. The Bentayga’s air suspension glides across the cobbled streets, however, as concert-goers gather in the Residenzplatz square. This is the perfect location to show off the Bentley’s 20-speaker Naim audio system with The Sound of Music soundtrack. There’s no hotel parking in the busy centre, so I wheel my suitcase to Hotel Goldgasse, an atmospheric hotel down a narrow shopping alley near the Domplatz. The medieval building is packed with character and super-convenient for the city centre.

The next day it’s an eight-hour drive to Belgrade. Judging by the welcome, I’m not sure there are many orange Bentleys in the Serbian capital. The understated Saint Ten Hotel is a 15-minute walk away from the city centre, in a leafy suburb. The Church of Saint Sava, one of the largest Serbian Orthodox churches in Europe, dominates the skyline and the hotel can arrange tour guides to explain the complicated past and present history of this much misunderstood country.

South of Belgrade the Serbian countryside becomes more undulating and tree-covered than the agricultural northern flatlands. There are long queues at the border into Bulgaria and to use the rugged roads south to Sofia you will need a vignette – a sticker to show that you have paid the correct toll.The Grand Hotel offers huge suites for reasonable prices. There’s a slightly austere atmosphere that harks back to the Communist era but the staff are helpful and Gurko Street is a good place to explore on foot.

While Orient Express passengers dine on lobster and caviar, I’m making the best of motorway cafés and service stations. Sadly, the Bentayga doesn’t come with a butler. The current Orient Express takes a leisurely six days to make the Bosphorus strait and I’m on schedule to beat that – until I receive a phone call telling me I don’t have the correct paperwork to drive the car into Turkey. I’m only an hour from the border, near the Bulgarian city of Plovdiv, last year’s European Capital of Culture. I’m forced to turn abruptly north and head for the Romanian capital of Bucharest instead. It’s been an exhilarating journey, driving the fastest, most luxurious SUV on the road – well, on Romanian roads for certain. If I were to do the journey again, would I let the train take the strain or choose the Bentayga Speed? I could live without the orange paintwork, but include a few smoked salmon sandwiches and I’d be happy to struggle by in the Bentley.

Bentley Bentayga Speed

Price: £182,200Engine size: 5950ccCylinders: 12Power: 626bhpPerformance: 0-62mph in 3.9 secsMax speed: 190mph