Alpina XD3 Biturbo vs Porsche Macan S Diesel - pictures

We go behind the wheel of the Alpina XD3 Biturbo and Porsche Macan S Diesel to see which fast diesel SUV is best. 

The Alpina costs £56,450, while the car in our pictures comes in at £59,985. 

It's powered by a 3.0-litre 6cyl diesel engine from the standard X3 xDrive35d, producing 345bhp. 

The XD3's BMW-based cabin is logically laid out and well equipped, but sat nav is extra. There are one or two clues as to the Alpina's identity, though. 

Back seats are comfortable, while the panoramic sunroof keeps the cabin feeling airy. 

Boot capacity rises to 1,600 litres with the rear seats folded. With them in place, the boot is 550 litres. 

Alpina has transformed the BMW X3 into a new beast entirely.

Changes over the standard X3 include a chunky bodykit, massive 21-inch alloys, unique badging and a sporty quad exhaust system. 

Reversing camera is an optional extra. 

You might think it'd be awkward to have the XD3 serviced, but identical mechanicals to the X3 means regular maintenance is available at any BMW dealer. 

Performance in the XD3 is sensational. It's incredibly rapid and feels much smaller than its size would suggest. 

It's not the most agile SUV on sale, but the XD3 has great levels of grip and plenty of composure. 

The Porsche Macan S Diesel is priced at £44,636 as standard, but our test car cost £56,845 thanks to all the optional extras it had fitted. 

It's powered by a 3.0-litre V6 diesel engine that produces 255bhp. 

Leather seats and real metal trim for the dash and doors give the Macan an upmarket feel. 

Despite its more compact exterior dimensions and swoopy styling, the Macan still has plenty of room inside. 

The Macan's boot isn't as big as the XD3's, at 500 litres, but there's still plenty of space and its square shape makes it very versatile. There is a higher load lip, though. 

The Macan stands out with its huge grille, swept-back lights and 911-inspired styling. 

Despite being diesel-powered, the Macan still gets a set of beefy quad exhausts. 

Real metal finish on the seat controls contribute to the upmarket feel. 

Macan lives up to the aggressive looks, with impressive agility and great performance. 

Quick, precise steering makes the lighter Macan more agile than the XD3, while little body roll and plenty of grip inspire great confidence to really throw the Macan round a series of bends and twists in the road.