Brabus has worked its magic and managed to squeeze 261 hp (195 kW) more from the biturbo V8 AMG engine. In order to unlock a mighty 838 hp (625 kW), the tuners had to increase the motor’s displacement from 5.5 liters to 6.0 liters and install upgraded turbochargers, among implementing other hardware tweaks.
Now with a jaw-dropping 1,070 pound-feet (1,450 Newton-meters) at its disposal, the heavily modified GLS63 dubbed “Brabus 850 XL” has 510 lb-ft (690 Nm) more torque than the standard version. At the same time, it also has more torque than GM's new 6.6-liter V8 Duramax rated at 910 lb-ft (1,221 Nm), and that's a diesel.
The extra power has lowered the 0-62 mph (0-100 kph) sprint time from the stock 4.9 seconds to just 4.2 seconds. The electronic top speed limiter, which is necessary due to tire limitations, is less restrictive now as it has been reprogrammed to kick in later, at 186 mph (300 kph) instead of 177 mph (285 kph).
But there’s more to this tuning project than the overhauled engine. Brabus has also developed a new body kit for the gargantuan 2.6-ton SUV. Beefier bumpers with carbon fiber accents are available along with a new front spoiler lip and a rear diffuser insert. A high-performance exhaust with four tips is also part of the package, as is the 23-inch set of wheels shod in 295/35 R23 grippy tires. The Mercedes-AMG GLS63’s air suspension has also been modified and it now has a new setting that will lower the high-performance SUV by 1.2 inches (30 mm).
Stepping inside the cabin, Brabus is providing a wide array of customization possibilities, including this brown all-leather cabin with braided-leather accents and checkered flag carbon touches. Buyers get to pick from a rich selection of wood and carbon inlays, as well opt for an aluminum finish for the pedals and door pins. The paddle shifters can also receive the aluminum treatment to provide a more solid feel for when the driver will want to manually switch gears of the GLS63’s seven-speed transmission.
This particular Brabus 850 XL was built to order for a client, but you can have one just like it, or ask the tuner to customize it in a different way. If you would rather keep it stock, here’s what our Managing Editor, Steven Ewing, had to say about the 2017 model year in a review from April.
Gallery: Brabus 850 XL based on Mercedes GLS
BRABUS 850 XL based on the Mercedes-Benz GLS
Luxury SUV with 625 kW / 850 HP, 1,450 Nm of torque, a top speed of 300 km/h and 23-inch forged wheels
Some like it extra-large and super strong: That is why BRABUS has now directed its attention to the top-of-the-line model of the new Mercedes GLS-Class, the GLS 63 4MATIC. The result is a supercar that could not be more representative of BRABUS. At the heart of the BRABUS 850 XL is a twin-turbo eight-cylinder engine with an increased displacement of six liters. An output of 625 kW / 850 HP (838 bhp) and a peak torque of 1,450 Nm (1,069 lb-ft) sling the exclusive SUV from rest to 100 km/h (62 mph) in a mere 4.2 seconds. In the interest of tire safety, the top speed is limited electronically to 300 km/h (186 mph).
Aerodynamic-enhancement components with a naked carbon finish and tailor-made 23-inch BRABUS Monoblock "PLATINUM EDITION" hi-tech forged wheels lend the high-performance 4x4 unmistakable looks.
The customization of the interior is just as exclusive, and features a BRABUS fine leather interior finished with consummate craftsmanship in every detail.
The BRABUS 850 6.0 Biturbo increased-displacement engine pumps out a phenomenal 195 kW / 265 HP (261 bhp) more than the underlying stock engine. The effort the BRABUS power unit engineers expend for this power upgrade is tremendous: more displacement translates into more power, and for this reason the company hi-tech engine shop increases the displacement of the eight-cylinder four-valve engine from stock 5,461 cc to 5912 cc (333 to 361 cu in).
To this end, the cylinder bore is increased to 99 millimeters (3.89 in) and the engine is fitted with correspondingly larger forged pistons. A special precision-balanced billet crankshaft in concert with forged high-performance piston rods increases the stroke to 96 millimeters (3.77 in). In addition, the engineers optimize the two cylinder heads of the V-8 for mixture flow.
The engine bay is dominated by the BRABUS 850 intake module, which is manufactured from carbon and is specifically designed for the BRABUS increased-displacement engine. It is complemented by two newly designed air filter boxes with larger intake cross-section. Sophisticated carbon air ducts supply the intake with fresh combustion air.
Just as crucial for the phenomenal performance upgrade is the newly designed forced induction system: the engineers developed modified exhaust manifolds to fit the engine with special BRABUS turbochargers with larger compressor units. To lower the charge air temperature, the intake tubes and charge pipes are fitted with special "Gold Heat Reflection" sheathing that stands out immediately.
The increased-displacement engine also includes larger downpipes with a diameter of 75 millimeters (2.95 in), and metal catalysts. The last link in the chain is the BRABUS stainless high-performance exhaust system with actively controlled exhaust flaps for an active sound management. Drivers can switch between a throaty V-8 exhaust note in 'Sport' mode and a discreet whisper in 'Coming Home' mode at a touch of a button in the cockpit. The ceramic-coated tailpipes sport the BRABUS logo and stand out from the crowd visually as well.
The perfect calibration of all high-performance components by the BRABUS power unit engineers and electronics specialists is the result of extensive bench and road tests. The professional execution of all work ensures not only an optimal power output, but also a long service life beyond reproach. BRABUS vouches for this with the exemplary three-year or 100,000-km/62,000-mile BRABUS Tuning Warranty.
BRABUS recommends high-performance lubricants from MOTUL.
The huge amount of work is reflected in unrivalled performance figures: a power output of 625 kW / 850 HP (838 bhp) at a low 5,400 rpm is equally a benchmark in this category of vehicles as is the phenomenal peak torque of 1,450 Nm (1,069 lb-ft), which is on tap on a flat plateau between 2,500 and 4,500 rpm.
As a result, the BRABUS 850 XL delivers a performance on par with a full-blooded sports car: From rest, the SUV weighing in at more than 2.6 tons accelerates to 100 km/h (62 mph) in just 4.2 seconds. Due to tire limitations, the top speed has to be capped electronically at 300 km/h (186 mph). BRABUS also offers two performance upgrades to 464 kW / 630 HP (622 bhp) or 515 kW / 700 HP (690 bhp) for GLS 63 owners disinclined to spending quite this much on engine tuning.
Of course, the aerodynamics, tires and chassis of the BRABUS 850 XL are also modified to match the tremendous performance. The BRABUS designers developed aerodynamically efficient and great-looking bodywork components made from hi-tech carbon material, which are available not only for the BRABUS supercar, but for all GLS 63 models.
The BRABUS front spoiler lip, which attaches to the lower part of the bumper, lends the SUV an even more striking face. What is more: The shape was optimized in the wind tunnel and reduces lift on the front axle at high speeds for further improved handling stability. Tailor-made air deflectors with integrated LED side markers upgrade the side air intakes in the front bumper.
The rear fascia is upgraded with a new carbon diffuser insert, which provides the perfect backdrop for the two dual tailpipes of the BRABUS high-performance exhaust. The BRABUS roof spoiler adds the icing to the cake.
BRABUS alloys for the GLS 63 come in various designs and sizes with diameters from 21 to 23 inches. BRABUS Monoblock "PLATINUM EDITION" hi-tech forged wheels of size 11Jx23 represent the most exclusive option. Thanks to state-of-the-art manufacturing technology, these wheels offer a perfect combination of lightweight construction and maximum strength. BRABUS technology partners Continental, Pirelli and YOKOHAMA supply the matching high-performance tires. The GLS 63 can be fitted with high-performance street tires up to 295/35 R 23 in size.
The BRABUS chassis engineers developed a special control module for the AIRMATIC air suspension to optimize the driving dynamics further and to give the vehicle an even sportier appearance by lowering the ride height of the BRABUS 850 XL and any stock GLS 63 by about 30 millimeters (1.2 in).
The luxury appointments of the BRABUS supercars of course also include an exquisite BRABUS fine leather interior. The interior appointments are tailored to customer specifications from a combination of especially soft and breathable Mastik leather and Alcantara. The vehicle featured here is fitted with a brown BRABUS all-leather interior with especially gorgeous braided-leather highlights to contrast with the black paint finish. The likewise brown BRABUS 'Checkered Flag' carbon elements in the cockpit are also color-coordinated with the leather.
BRABUS wood or carbon inlays, which can be produced in every conceivable variation, add a particular individual note. Aluminum components such as pedals and door pins highlight the sporty character of the vehicle. BRABUS offers special aluminum paddle shifters with RACE design for even more precise gear changes when operating the SPEEDSHIFT PLUS 7G-TRONIC automatic transmission manually.
The BRABUS 850 XL is built to customer order. Alternatively, any GLS 63 can be converted to this specification all at once or in stages.