Cadillac Optiq vs Mercedes-Benz GLC300

What's the difference?

A taste test, but so far so good for the Cadillac Optiq, which is already my favourite model in the Caddy range. More space than you think meets a lovely cabin experience and a punchy powertrain.

Note: CarsGuide attended this event as a guest of the manufacturer, with accommodation and meals provided.

Note: The author, Andrew Chesterton, is a co-owner of Smart As Media, a content agency and media distribution service with a number of automotive brands among its clients. When producing content for CarsGuide, he does so in accordance with the CarsGuide Editorial Guidelines and Code of Ethics, and the views and opinions expressed in this article are solely those of the author.

The GLC300 Coupe isn't quite as great when it comes to being a family car as the regular SUV version of the GLC, and that's purely down to the sloping roofline which not only makes access more difficult to the second row but reduces boot capacity.

That said, the GLC300 Coupe makes a much better family car than a Mercedes-Benz C-Class sedan, or any sedan.

Easy and enjoyable to drive, packed with great features and still practical, the GLC300 Coupe would still cut it as a good family car.

I really like the exterior of this Optiq, and especially the front-on view, with its vertical DRLs and that bold Cadillac grille delivering real medium SUV street presence. 

You could argue the side profile is a little more vanilla (discounting the big wheels, of course), but it looks swept-back and sporty, and not as though it has been designed exclusively for aerodynamics above all else. That's a compliment, not an insult. Cadillac's engineers say every line and crease has been developed to help it slip through the air, but it does it without looking like a science experiment. 

The material choices inside are lovely, too. The brand says it has focused on sustainable and recycled materials (the centre console is made from tulip wood and recycled newspaper, for example), but the highlight in my test car was the fabric derived from recycled polyester fabric that lined the door panels and much of the dash. It's a refreshing (and comfy) departure from the norm.

Less positive is the level of Mar-a-Lago bling dotted elsewhere in the cabin, like the chrome ringed centre console and silver-tipped vent controllers. They jar with the otherwise dark, calming and modern-feeling space.

There are physical buttons galore, controlling all your climate settings along with steering-wheel controls as shortcuts for key functions, but there is also still a bit of on-screen action for things like quick access to your driving modes.

The tech looks fab, though, with the curve through the screen looking intentional and elegant and way nicer than the tablets plonked in a lot of EVs these days.

Coupe SUVs aren’t for everybody… they’re not even for lots of people. But the design of an SUV with its roof cut down so that it meets the tailgate at an almost sportscar-like angle appeals to more than a few fans. The thing is they don’t just like the look, they love it, and they also probably enjoy how much the styling makes other people cranky.

To my eyes the GLC300 Coupe is the best execution of the bodystyle compared to those of BMW and Audi. There’s an elegance to the GLC300 Coupe and the AMG-line adds a tough look that only enhances the solid, powerful but pretty look.

The GLC Coupe is a mid-sized SUV and this new generation model is a bit bigger the previous one and now measures 31mm longer at 4763mm end to end, it’s 1890mm wide, 1605mm tall and has a wheelbase of 2888mm.

It’s also more aerodynamic than ever. No seriously, it’s drag coefficient is now 0.27 and it looks like a bar of soap - and it's about as slippery as one, too.

More curved surfaces await inside with a dashboard that pours down into the large centre console and it's adorned with a sloping and large portrait-style media screen. 

At night or in tunnels the ambient lighting glows through the air vents and skirts the edges of the door trims, console and dashboard.

It’s a minimalist and high-tech cockpit with modern sports seats up front and a Nappa leather wrapped steering wheel with its twin blade design.  

So, how does the coupe design work for family practicality? Let’s take a look.

The Cadillac Optiq is around 4.8m long, 1.9m wide and 1.6m high, which is slightly longer than your average mid-size SUV. And I would argue most of that extra space is located in the back seat, where – at 175cm – I had no problem stretching out behind my own driving position. There was plenty of knee room and, thanks to a virtually flat floor, no bulky tunnel getting in the way for the middle-back rider, either.

Headroom could be a touch more challenging. It was no issue for me, but there wasn't a ton of clear air between the top of my head and the raked roofline, so six-foot-plus passengers might be stooping. Still, if your kids are six-foot-plus, get them into the NBA and have them buy you a car instead.

Elsewhere in the back there are cupholders in the pull-down seat dividers, ISOFIX attachment points in each window seat and twin USB-C ports. There are air vents but no temp controls for backseaters.

The boot is sizable, too, with Cadillac promising 744 litres of cargo space with the rear seats in place and 1603 litres with the rear seats stowed flat. And kudos for not just providing a neat charging cable space under the boot floor, but also giving you a little zip-up suitcase to store it in.

SUVs are the most practical cars for families because of the better access to the cabin thanks to their large doors and slightly elevated ride height, their big boots with wide and tall hatch openings and their high flat rooflines. They’re essentially raised station wagons.

A coupe-style SUV still has four doors but they are less boxy due to the sloping roofline which falls away quickly to meet the tailgate at a lower point. The effect is a sporty-looking shape but practicality is lost in this exercise of form over function.

The second row doorways aren’t as large as those on the regular SUV. I did a side-by-side test and felt like I had to duck under the sloping roof when getting out of the back seat.

The smaller opening also made it trickier to lift my toddler daughter into her baby seat.

The sidesteps are also surprisingly handy for bigger kids and my eight-year-old used them every time when climbing into the car.

Cabin storage is outstanding with huge door pockets and cupholders in both rows, and while the 545-litre boot in the GLC300 Coupe is 80 litres smaller than the cargo capacity of the regular GLC SUV, it's bigger than the previous version of the Coupe.

As for people space, there’s enough headroom for me at 189cm tall in the back seat and heaps of legroom, even behind my driving position.

I’ve mentioned the lack of climate control in the second row, but also should point out that there are no USB ports back there either.

There are USB ports in the big centre console box upfront and a long cord should be able to make it to the second row. 

There’s a wireless phone charger but it's housed in the bowels of the centre console too, and you’ll need to weave your hand while clasping the phone under the shiny black trapdoor, past the cupholders possibly with drinks in them and almost under the dashboard.

Mercedes-Benz is offering Australia just the GLC300 grade in both the SUV and Coupe body styles.

High-performance AMG variants are out overseas now and will arrive in Australia soon, too.

You can expect to pay more for these AMG beasts - a lot more than the $113,900 list price of the GLC300 Coupe.

Still the GLC300 Coupe does come standard with an AMG Line body kit and 20-inch AMG alloy wheels. LED headlights are also standard, so is the panoramic glass roof, tinted rear glass, proximity unlocking and a power tailgate.

Inside there’s synthetic leather Artico upholstery, sports heated front seats, Nappa leather steering wheel, an 11.9-inch media display with Apple CarPlay and Android Auto, a 12.3-inch digital instrument cluster and a head-up display. There’s also dual-zone climate control and wireless phone charging.

The value is good in terms of features, although the price is slightly higher compared to the rivals such as the BMW X4 xDrive30i ($106,400) and Audi Q5 Sportback 55TFSI ($110,200).

It’s worth pointing out, too, that the GLC300 Coupe is about $10K more than the GLC300 SUV version. Why? The coupe versions of prestige SUVs always tend to be pricier than their regular more boxy SUV siblings. Somebody in marketing will be able to explain why.

Having lived with the GLC300 Coupe with my family over the past few days I can say the proximity unlocking which works by touching even the back door handles is excellent, the tinted windows are dark and cut out much of the sun's glare, but there’s no climate control in the second row. There are air vents back there, which is good.

I found that on hot days the semi-transparent shade on the glass roof couldn’t stop the cabin from heating up quickly.

There is only one trim level and powertrain on offer in the Optiq, called the Sport AWD, and with it comes dual electric motors – one on each axle – delivering a total 224kW and 480Nm. 

That's enough, says Cadillac, to push the Optiq to 100km/h in a hot-hatch-feeling 6.3 seconds and on to a top speed of 210km/h.

The GLC300 Coupe has a 2.0-litre four-cylinder turbo-petrol engine making 190kW of power and 400Nm of torque.

There’s also an overboost function which allows the engine to make an extra 17kW and 200Nm just for a brief moment, but that extra dollop of grunt combined with the regular output provides impressive acceleration (0-100km/h in about 6.3 seconds) for overtaking or moving quickly when you need to.

A smooth nine-speed automatic transmission sends the drive to all-four wheels.

The GLC300 Coupe is all-wheel drive and while there’s a setting for rougher terrain, along with one for comfort, eco and sport, but I’d make sure that it doesn’t get any more adventurous than tame gravel and dirt roads.

Mercedes-Benz refers to the GLC300 Coupe as a mild hybrid and this is because it has a 48-volt system and an integrated starter-generator.

This type of hybrid doesn’t use electric motors, doesn’t drive the wheels and won’t save much fuel, but it will provide efficiencies by supporting the engine and when coasting, plus will reduce petrol consumption to a small degree.

The downside of the Cadillac EV experience arrives here, with surprisingly slow charging speeds for a vehicle in this class. Remember, Australia's fastest DC chargers are rated to 400kW, and a vehicle like the BMW iX3 will accept it, taking you from 10 to 80 per cent charged in 21 minutes.

The Optiq, though, is rated to just 110kW, which feels a bit odd. The brand doesn't quote a 10 to 80 per cent time and instead says you'll accrue "up to 94 kilometres of range in 10 minutes".

Still, most people charge at home, and there the Optiq can be plugged into anything from a regular wall socket to a super-fast 22.1kW three-phase AC wallbox. 

The brand is promising a total 425km WLTP driving range with a fully charged battery.

As we mentioned above the GLC300 Coupe's 48-volt mild hybrid system is not the kind of hybrid that will allow you to drive miles on electric power, nor will it dramatically reduce fuel consumption in the way a parallel, series or plug-in hybrid will. But every bit of efficiency helps.

Mercedes-Benz says the GLC300 Coupe will use 7.7L/100km after a combination of open and urban roads. 

We had the GLC300 Coupe for just two days, but in that time my family covered 176km of regular daily usage which took in motorways but mainly suburban duties such as the school run, supermarket dashes, that sort of thing.

In our fuel test we measured 14.48 litres at the fuel pump which works out to be an on-test fuel use figure of 8.2L/100km and not far off the manufacturer’s claim. 

While this fuel consumption isn’t overly high, a plug-in hybrid or even a parallel or series hybrid could return about 5.0L/100km or less.

Mercedes-Benz has dropped plug-in hybrids from its Australian range which is a shame because it would be good to see more efficient options in the GLC range. Of course if you want more efficiency from a Benz of the same size, there is always the fully electric EQB or EQC.

First things first, this was a limited test of the Optiq, mostly stop-start Sydney traffic, so you’ll have to wait 'til we get the Caddy through the CarsGuide garage for a full and thorough test for a detailed driving review. But on first impressions, the signs are good for the Optiq.

The power delivery is rich and plentiful, and while it’s not aggressively fast, there’s more than enough punch from the line to get you up and moving in traffic.

It rides well, only feeling a bit brittle over properly rubbish road surfaces, and it offers a refreshing sense of connection to what’s going on beneath the tyres.

The steering can feel a little vague on-centre, however beyond that it feels direct but not darty, with a nice weight to the movement. 

The active noise cancellation and sound deadening appear to be doing their roles well, too. I drove past a roadworks site, and most of the drilling occurring outside was banished from entering the cabin. Impressive stuff.

Again, I want to spend more time with the Optiq before passing full judgement, but so far so good – it's my favourite of the Cadillac products to date.

There’s a lot to like here but the short version is the GLC300 Coupe has a comfortable ride, but good handling, with a responsive engine, although rear visibility through the small back window is poor.

If we drill down a bit further I can tell you that excellent cameras around the car will help you check to make sure kids aren’t running around behind you and that forward and side visibility through the window is good.

An important takeaway is that the GLC300 Coupe is easy to drive with light steering and an engine that’s mild and controlled in its power delivery.

The gear shifter is mounted on the steering column, in the same way an indicator lever is. So putting the car into Drive, Reverse and Park is so easy and means you don’t have to take your hands off the steering wheel. 

As a family car I liked the good body control and composed ride. We have a small toddler that we can sometimes only get to sleep by taking her for a drive and we found that she could nod off and not be woken by potholes and speed bumps or too much leaning in the corners. 

The GLC was given the maximum five star ANCAP rating in 2022. There’s AEB, active lane keeping assistance and active blind spot warning and nine airbags including a centre airbag.

As mentioned above I especially liked the surround-view camera systems - which let you look right around the car - good for driveway safety and kids.

For child seats you’ll find two ISOFIX mounts and three top tether anchor points in the second row.

I was also impressed to see a space-saver spare wheel under the boot floor and not just a puncture repair kit. 

The Cadillac Optiq is covered by the brand's five-year, unlimited-kilometre warranty, which lags the similarly sized and priced Hyundai Ioniq 9 and Kia EV9, but is on par with the Germans. There's also five years of roadside assistance, while the battery is co vered for eight years or 160,000km. 

Service intervals are 12,000km or 12 months, and the brand says it is still finalising service pricing, so that’s something to ask about before you commit.

Rather than conventional dealers, Cadillacs are typically sold online with hands-on inspection at 'Experience Centres' - currently one in Sydney and one Melbourne. Service and test drive sites are also in place in Brisbane, Canberra, Adelaide, Perth and Hobart.

The GLC300 is covered by Mercedes-Benz's five-year, unlimited-kilometre warranty. 

Services are annually or every 25,000km. And you can buy a three-year service plan for about $3000.