All-New GLB: Arctic Tests, Cosy Cabin Tech And Space
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They have driven it into a freezer and turned up the weather until it behaved like an angry Arctic hare. The all-new GLB is currently undergoing its paces in the climatic wind tunnels at the Mercedes Technology Center in Sindelfingen, with a world premiere set for 8 December 2025. If you like skiing, or the idea of not freezing to death on the way home from a mountain, this is reassuring news.
Testing At The Limit: Arctic Temperatures And Blizzard Simulations
The cold tunnel will happily play host to temperatures from minus 40 to plus 40 degrees Celsius, which covers just about everything nature can throw at a steerable box on wheels. Snow cannons conjure different types of snow, and a fan will hurl it at the car at up to 200 km/h to recreate proper blizzard conditions. Underneath, a rolling road driven by powerful electric motors lets 4MATIC models behave exactly as they would on real snow. The rigs can deliver up to 780 kW and simulate speeds up to 265 km/h, while vehicles can be refuelled or charged inside. The whole operation sits in a 70 by 60 metre building with a control room where technicians tweak temperature, humidity and wind speed while watching through big insulated windows. It looks serious, because it is.
Quality In Heat: Desert Sun And The Hot Road
If the test lab was only good at frost, it would be useless. So there is also a heat chamber that runs from minus 10 to plus 60 degrees Celsius and a solar simulator with 32 lamps, producing radiation between 200 and 1,200 watts per square metre. That top end is comparable to the sort of sunlight only found in exceedingly hostile places, such as Death Valley. There is also a Hot Road, a simulated surface heated to between 50 and 70 degrees Celsius, to reproduce the kind of tarmac that cooks your tyres on a very bad holiday. The point of all this is simple: make the GLB see everything before real people do.
Real Winter Checks: Wipers, Intakes And Defrosting
The winter tests are utterly practical. Engineers check whether wipers clear snow reliably, whether swirling spray from passing lorries blocks air intakes, and how quickly heating systems can de-ice a windscreen. The new GLB performed well. At minus 15 degrees Celsius the defrost setting alone cleared the windscreen enough to drive off in 15 minutes, and that was recorded on camera for posterity. In short, visibility and thermal comfort are not left to hope.
Heating Efficiency And Intelligent Climate Control
The new GLB has learned how to warm up in a hurry. On a 20 minute run at minus 7 degrees Celsius it heats the cabin twice as fast as the old model, and faster than a comparable conventionally powered car. The electric version needs about half the energy of its predecessor, which is good news for range. The system prioritises warming the upper body and hands first, so you feel comfortable quickly. It also adapts to what you are doing, whether you are charging, sitting in the car or taking a nap, by using a predictive strategy that tweaks heating and cooling automatically.
At the heart of this is an improved heat pump, borrowing technology from a high-efficiency programme. It is a multi-source unit that draws on waste heat from the drive and battery, plus ambient air. Using that free heat means it runs at roughly a third of the electrical energy that a conventional auxiliary heater would need for the same output.
Interior: Superscreen, Floating Console And Thoughtful Controls
Inside, the GLB has shed sculptural fuss in favour of a cleaner, more purposeful look with high-tech details. The optional floating MBUX Superscreen spans the dashboard and gives the interior a modern, slightly sci-fi feel. Circular vents finished in Silver Shadow look sporty and appear to float, while the centre nozzle replaces old louvres with a flat modern form. Doors are recessed with roomy, floating centre panels and open storage. The centre console is a three-dimensional surface with options for luxurious trims, a smartphone storage area with wireless charging, and neat cup holders. The steering wheel has been redesigned to be more ergonomic and more intuitive, including a rocker switch for the limiter and distance assist, plus a roller for audio control, responding to what customers asked for.
Space And Flexibility: Five Or Seven Seats
The GLB remains available as a five-seat or a seven-seat car, and it genuinely has grown up in the headroom department. Thanks to a refreshed roofline and a standard panoramic roof, the first two rows feel noticeably airier. The second row offers more legroom and longer thigh support, and for those who like to tinker there is a longitudinally adjustable rear bench that is optional on five-seat models and standard on seven-seat versions. Backrests can be reclined to several angles and the whole row moves forward or back to favour passenger comfort or luggage capacity. The optional third row is easier to access than before, and if you do not need the extra seats they sink neatly into the load floor.
Panoramic Roof With Adaptive Privacy And Starry Lighting
The panoramic roof is heat-insulating laminated safety glass with an infrared-reflecting LowE coating that helps keep the cabin cool in summer and reduces heat loss in winter. The infrared film is astonishingly thin, around 200 nanometres. As an option, the glass can change transparency segment by segment in 10 to 20 milliseconds, switching from clear to opal for privacy or glare protection, controlled via the central display. For those who like a touch of theatre, the roof can be illuminated with LED modules that create a personalised starry sky linked to the ambient lighting.
MB.OS, MBUX And Driver Assistance
The digital experience is refreshed under a new operating system that makes the GLB feel smarter as you spend time with it. The fourth generation MBUX brings redesigned welcome animations, Zero Layer for quicker access to functions, a suite of apps, a virtual assistant with emotionally responsive avatars and generative intelligence, plus navigation powered by Google Maps and 3D surround mapping. Driving assistance is bundled under a single name and runs on substantial hardware: eight cameras, five radar sensors, 12 ultrasonic sensors and a water-cooled high-performance computer with headroom for future functions and over-the-air updates. Some features will be available at launch, others will roll out later as digital extras that can be added or updated after purchase.
In short, the new GLB has been put through the full range of meteorological misery and come out the other side more comfortable, more efficient and more adaptable. It is ready for the mountain, the motorway and the Mediterranean, and it will do so with a level of polish that the engineers tested until the cold made the coffee taste like icicles.
Zachary Skinner is the editor of TechDrivePlay.com, where tech, cars and adventure share the fast lane.
A former snowboarding pro and programmer, he brings both creative flair and technical know-how to his reviews. From high-performance cars to clever gadgets, he explores how innovation shapes the way we move, connect and live.
