Mercedes-Benz GLC review

For entirely steel-sprung cars, Mercedes is only offering its ‘Sport’ springs in the UK. This is a knock-on effect from Mercedes only selling the GLC in varying shades of AMG Line specification over here. Interestingly, other markets, such as Australia, go the other way, taking only the ‘Comfort’ springs.  GLCs that aren't fully fledged AMG models also use passive dampers all-round.

Another knock-on effect of AMG Line trim is a minimum wheel diameter of 19in, rather than the 18in that less sporty trim levels can be fitted with.

Our test car is a mild-hybrid 255bhp 300 in AMG Line Premium Plus trim. Like every GLC, it also has two driven axles, with a permanent torque split that marginally favours the rear. Torque is syphoned off from the nine-speed automatic gearbox, through a transfer case and to the front axle. This car also rides on 20in wheels – an inch larger than standard and the largest offered.

On our scales, it weighed 1929kg, just 4kg more than the claimed figure and 36kg less than the non-hybrid, less generously specified 250d we road tested back in 2016. The plug-in hybrid 300de is understandably heavier still, tipping the scales at a claimed 2385kg.

Comfort & Isolation

When the original GLC arrived in 2016, we criticised its AMG Line suspension for its brittleness on poorer surfaces. Seven years later, we have similar complaints – albeit lesser in severity. While the new GLC has a fine primary gait, the steel coils of its AMG Line suspension (which are undoubtedly not helped by our test car’s 20in wheels) still struggle to isolate you on rougher roads and some unwelcome sensations travel up the steering column.

This brittleness seems to be a classic case of setting a car up for German roads, with little thought to how it might fare in the UK. None of this is massively pronounced, but it is noticeable, so while Mercedes should be leading the field when it comes to refinement, in this case the product is mostly fine but isn’t notably, if at all, superior to the BMW X3 et al. Tellingly, a C-Class on 19in wheels out-rides a GLC on 20in wheels in almost all cases. Plug-in cars fitted with air springs on the rear axle feature a little more compliance over well surfaced but undulating Tarmac, but not enough to recommend one set-up over the other.

In terms of outright isolation, the GLC isn’t perhaps quite as strong as you might expect from Mercedes, either. The engine is docile at idle, but at a 70mph cruise, the 300 (69dBA) couldn’t beat even the BMW X1 xDrive23i (67dBA) – on M Sport suspension, no less – that we tested earlier this year. The diesel engine in the 300de is equally refined in normal use, only making itself a nuisance when vocally extended at high revs. Happily, with so much mid-range torque there's very little reason to work the 2.0-litre unit hard.

However, there's no doubting the 300de (and its petrol equivalent, the 300e) make cost effective company car choices. With a Benefit-in-Kind rating of just 5%, the PHEV will cost user choosers around £3,000 a year less in tax than the cheaper-to-buy and slower 220d version. That said, the petrol 300e is less expensive still thanks to its lower list price, so you'll really have to want the diesel's slightly superior internal combustion efficiency to justify the extra outlay.