Mercedes GLC 350 d vs. Audi Q5 3.0 TDI, BMW X3 30d: Clean 6-cylinder diesel SUV comparison test

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The new BMW X3 30d is challenging the Audi Q5 3.0 TDI and Mercedes GLC 350 d in the first Auto motor und sport comparison test. These three middle-class SUVs come with powerful six-cylinder turbo diesel engines, all as clean as Snow White.

Some say diesel is the steam engine of our day. At around 40 percent, diesel engines have the highest efficiency of conventional internal combustion engines. Unhysterically, six-cylinder diesels are magnificent engines: powerful, efficient, clean and slightly over-engineered to boost the performance from enough to enjoyment. Let’s start testing. And let’s celebrate perhaps the best engines that will ever be in this class.

Q5 and its strive for perfection
The Q5 is a car that looks as if it wants to make everything a science. The quest for perfection pushes every detail. Whatever is possible, the Q5 is ready to illustrate: digital instruments whose pixels are able to mimic the look of thin paper, an infotainment that wants to omit no function, even if it then gets too complex because of the many nested submenus.

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More tangible are the flawless workmanship and the stylish material quality of the interior furniture. There is also plenty of space. Driver and passenger get sublime seats – a little too high maybe. On the well-formed rear seat, two passengers are accommodated comfortably. For this purpose, the Q5 drives on all known variability tricks: inclination adjustment for the backrest, longitudinal displacement for the bench – although there is barely enough room to advance at a standard seat space of 71 cm. The backrest can also fold down into three parts remote-controlled.

Now back to the driving experience. Press the start button. As if from far away, the V6-TDI comes to life. Pull the selector lever back, and the Q5 just goes forward – urgently and vehemently, but so cultivated and homogeneous at the same time, that the force does not seem so powerful. This is due to the automatic gearbox, which changes over-zealously through its eight steps. It diminishes the impression of the sovereignty of the drive without increasing the dynamics. It is not very noticeable when it comes to landing gear on the highway. The Q5 remains neutral for a long time, always safe and yet always well below the expectations that people indulge in when they know how fast and precise they can drive the Q5 on a test track with 21-inch wheels through slalom and lane changes.

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On the road, the steering feels distanced and emotionally cold, despite its directness. One experiences so little – also because of the impeccable traction. The 3.0 TDI gets real, permanent four-wheel drive instead of the switching Ultra Quattro of the weaker Q5s. After all, on bad routes something is going on. Because of the high breakaway torque and large wheels, the air suspension (1,950 euros) responds harshly to minor bumps, oscillating in comfort mode over long waves. In Dynamic mode, it reduces that feeling.

Do not get us wrong, all these are tiny flaws on an outstanding car that strives for perfection everywhere, in terms of comfort, dynamics, space, variability, style, safety, speed and efficiency. That brings it far forward, but this perfection is too cool.

X3 and the new sports order
By contrast, the X3 has always been the SUV that fuels the fire of passion. With all the variability, the lush space and the better view the X3 was always just about lifting the brand-typical dynamics to another level – one with now 20.4 centimeters of ground clearance.

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Again, the X3 wants to stir no gravel roads, but its driver. But let’s take a look at its body, which has grown to 4.71 meters. The X3 now accommodates five passengers without pressure and offers a well usable and cleverly expandable trunk (three-part folding seats with tilt adjustment by 18 degrees and cargo position). On the heavily contoured, gently elevated rear seat, the view is perfect. The front sports seats also ties the driver intimately to the car.

In operation, the innovation is limited to a few resorted keys. The infotainment can be controlled via a rotary-push-button and voice control and now via touch screen and also a somewhat strange fumbling with gestures. Nevertheless, one gets entangled sometimes in the many menus and submenus, which emerged with the permanent feature enhancements.

Maybe we are oldschooling there, but we really are not impressed by this typewriter display remote control key, which probably has more processor power than the 1986 base module DOS-7 of the Mir. All the more beautiful that it is not such trivialities that characterize the X3, but one main thing: the drive. The inline six-cylinder with variable turbo geometry and two flow channels (twin scroll) has 2,500 bar pressure in the common-rail injection, all while power was increased by seven horsepower and 80 Nm. It cleans the exhaust gases not only like the others with SCR-Kat and urea injection, but also with a NOx trap. And the engine, of the engine goes like a train.

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The three-liter X3 pushes even more energetic, powerful and faster than even the 21 hp stronger Audi. Meanwhile, the automatic switches so accurately, discreetly and quickly through its eight stages that there is never reason to interfere with the paddle shifters. The X3 was never a car in which one drives around only, but in which one likes to participate in the locomotion. To keep it that way, BMW has reduced the unsprung masses of the double-joint tie rod front axle and the five-link rear axle, and has also trimmed axle kinematics and the electromechanical power steering system for greater dynamics and feel.

In addition, the X3 M Sport offers larger brakes, the variable sport steering and the performance-controlled, wheel-selective power distribution on the rear axle by braking intervention. A sports suspension is standard on the M Sport, but the test car comes with the Adaptive suspension (600 euros). In any case, it should not be lacking in dynamical talent. And indeed, despite the lush dimensions the X3 feels more agile than the others. It bends smoothly and very precisely in curves, avoids understeer. This does not change the fact that the X3 is a power machine on the highway – always enormously powerful because of the brilliant engine. However, in addition to the force, the noise sometimes comes to the fore.

Because of the tight chassis, the suspension reacts harshly, short bumps being overturned hard. In addition, the sharpened precision of the feedback-intensive steering at high speed changes into fidgetiness. From the middle position, the steering response is delayed, to react all the more biting. But traveling with the X3 on an afternoon from Garmisch to Kiel? Always with pleasure, with good sound insulation and extensive assistance security – such as the reliable steering and guidance assistance. Is that enough, despite the high price, to go full speed ahead?

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GLC and relaxation tips
Because then we climb into the GLC, which continues the traditional Mercedes virtues: durable functionality, absolute safety, outstanding comfort. Just short of the shortest, it looks smaller from the outside than the others. Inside, it offers almost the same amount of space and the best standard seating space. When we take boot volume into consideration, the three models are on par. On the cuddly three-seater sofa in the back as well as on the armchairs in front passengers travel on long-distance comfortably and with enough grip.

The GLC is quite a solid event. It fits that the three-liter V6 starts quite unfashionably by turning the key and then pushes ahead with an authority that can only come from the depth of the displacement and the power of the turbocharger. Even at 3,400 / min, the diesel has its maximum power still gushing, with the 620 Nm already available at 1,600 tours. The GLC is indeed smaller than the others, the sovereignty of the engine thereby is only the greater – this meticulous attention is supported by the automatic, soft and pinpoint switching through its nine stages. Of course, the GLC is really fast too. But here, too, the surprisingly efficient engine (8.9 l / 100 test consumption compared to 9.0 in the Audi and 8.8 in the BMW) promotes not only the speedy arrival, but also the pleasurable journey on the road.

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Meanwhile, the air suspension (2,261 euros) flies over all bumps, softly and without vibrations, retaining even more comfort in the very dispensable sports mode than the BMW in the comfort curve. Anyone expecting tranquility in handling matters from the GLC can wait a long time. Because the Mercedes is the best driver car here. Period.

This is achieved mainly by the supple steering, which controls the car precisely, never poisonous, direct and yet homogeneous, with strong feedback too. And while the Q5 always keeps you aloof, as the X3 constantly tries to charm and incite you with its agility, the GLC turns alert, brave, but always unshakeably safe across the country, on the other hand stoically sovereign on the highway.

In the end, the three amazingly different SUVs are at a surprisingly similar, high level. The fact that the Q5 wins with perfection and space, does not change the fact that you also enjoy the X3 and GLC with their steam and that – it has to be – to the fullest.

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1. Audi Q5 3.0 TDI Quattro
462 points
The Q5 wants everything and can do a lot. With best space, variability and vehement brakes it wins, trying to hit perfection.

2. Mercedes GLC 350 d 4Matic
459 points
The GLC can do a lot, but does not show it right away. Surprisingly it also combines comfort and driving pleasure in the most harmonious way. Less space / variability.

3. BMW X3 xDrive 30d
456 points
Dynamism also characterizes the third generation of the X3, which makes huge gains in terms of space and quality, but does not quite reach the perfection of the Q5 and the harmony of the GLC.

Technical Data

  Audi Q5 3.0 TDI Quattro Mercedes GLC 350 d 4Matic  BMW X3 xDrive30d M Sport
Base price 57.150 € 54.228 € 62.700 €


Lenght x width x height 4663 x 1893 x 1659 mm 4656 x 1890 x 1639 mm 4708 x 1891 x 1676 mm
Trunk volume 550 to 1550 l 550 to 1600 l 550 to 1600 l
Engine 2967 cm³ / 6-Cylinder 2987 cm³ / 6-Cylinder 2993 cm³ / 6-Cylinder
Power 210 kW / 286 PS at 3750 rpm 190 kW / 258 PS at 3400 rpm 195 kW / 265 PS at 4000 rpm
Top speed 237 km/h 238 km/h 240 km/h
0-100 km/h 6,1 s 6,1 s 5,6 s
Consumption 5,7 l/100 km 5,9 l/100 km 6,0 l/100 km
Test consumption 9,0 l/100 km 8,9 l/100 km 8,8 l/100 km