Mercedes GLC review: six-cylinder GLC350d driven

A Mercedes-Benz GLC? What’s new? 

Nothing. The GLC has been around for a while now, and so has Mercedes’ 3.0-litre V6 diesel engine. They’re both very good in isolation, so one would assume that a GLC so equipped with said engine, rather than the usual four-cylinder diesel, would be a rather lovely thing. 

And is it?

Oh yes. More cylinders equals better in cars like this. Not that the four-cylinder isn't lovely in its own way, but more cylinders means more smoothness, more speed and a better noise. You’re looking at 254bhp, 0-62mph in 6.2secs, 148mph and an incredibly healthy 457lb ft of torque from just 1,600rpm. Not much more power, then, but just shy of 100lb ft more than you get in the torquiest four-cylinder GLC. That makes a difference - and because the nine-speed auto is seldom caught out (it operates as smoothly and unobtrusively as you'd hope. We think better than in four-cyl cars), there's power wherever and whenever you need it. Outright speed isn't its thing, but the way it builds is satisfying enough.  

Four-cylinder diesels always sound strained, however much power they have. The six never does, it sounds expensive. Quieter and more refined than, say, a 3.0-litre Jaguar F-Pace, not least any four-cylinder you care to mention. Except maybe Mercedes’ own, which as of right now is only available in the E-Class... 

So this is the GLC to have? 

If you don’t fancy the GLC 43, and spending a few extra grand (around five of them) is of little concern, absolutely. It’s no more of a driver’s car than a regular GLC (this is not an Audi SQ5 rival - unlike the 43 there are no real chassis or suspension mods), but the six does add a layer of desirability to an already quite desirable car. It feels like a more premium, more solid product with the six. However quiet, however refined you make a four, there’s still something incongruously agricultural about them. Granted the four will be a more economical car and cheaper to tax, but Merc quotes 47.9mpg for the 350 (56.5 for the 250), and that's not bad. We saw 44mpg on a run. 

Why Mercedes don’t offer this engine in the C-Class too is a complete mystery to us. Purely anecdotally, the number of BMW 330ds you see on Britain’s roads suggests the demand is there. 

Tell me more about the GLC. 

It’s a quality product this, if a bit remote to drive. Interior’s nice though – much like the C-Class’s. Read our full review for all the info. Save for the engine, the 350d drives just like its less powerful equivalents.