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A Stage 1 remap takes the 585hp GLS 63 AMG to around 660bhp and 1,100Nm on our rolling road, and the later 612hp 63 S to about 690bhp. The diesels gain proportionally more where it matters on a car this heavy: the 400d goes from 330hp and 700Nm to around 410hp and 840Nm, and the 350d from 258 to about 305hp and 770Nm. On a three-tonne car the torque figure is what changes how it drives.
Measured on our Mustang AWD rolling road in Maidstone. Wheel figures, drivetrain loss added for the flywheel numbers.The Mercedes GLS 63 AMG is a monster right out of the factory. With quoted figures at 575BHP and 760Nm torque, and the car weighing over 2.5 tonnes, it’s no wonder everyone loves it. The car, which could better be described as a bus, launches from 0-62mph in just 4.5 seconds. With a beast this fast, there was only one logical thing for us to do: make it even faster of course.
Mercedes GLS 63 AMG Stock Results
Mercedes claim that out of the factory, this car should produce 575bhp/760Nm torque as stated above. We know that German car manufacturers generally understate their figures. We expected increased stock results knowing how understated the German manufacturers are.
Just as predicted, when we squeezed the car onto the dyno (literally!) and gave it a few runs, we found that the car was actually making a little over 600bhp and almost 830Nm torque. Needless to say the owner of this car was happy to hear that in fact he already had a more powerful car than he originally thought! We next data logged the engine parameters on the dyno to help calibrate a map for the engine.
The Tuned Results
After several hundred map changes and lots of fine tuning we were set for the final dyno runs on the GLS AMG. As the dyno graph shows, this engine was very tunable. The car actually made an additional 50bhp and 200Nm torque! This means the AMG is now producing 650bhp and over 1000Nm torque with just a performance tune! This really gives the car an extra kick when accelerating. The Mercedes GLS 63 AMG with our stage 1 tune gains a lot of torque but keeps the ride smooth and luxurious, whilst at the same time being able to beat most road cars in a straight line as any good AMG should.
Use the button below if you would like your own GLS 63 AMG on our dyno.
Photos from the build
6 photos of this Mercedes GLE 2015 - 2019 in our Maidstone workshop. Tap any to enlarge.
Questions we get asked
How much power does a GLS 63 AMG gain?
The 585hp version goes to around 660bhp and 1,100Nm, and the 612hp 63 S to about 690bhp and 950Nm. The 4.0 twin-turbo V8 responds well, and the torque increase on the earlier car is the striking part.
What about the diesel GLS?
The 400d goes from 330hp and 700Nm to around 410hp and 840Nm. The 350d goes from 258 to about 305hp and 770Nm, or 286 to 345hp on the later car. On a vehicle this heavy, and especially towing, that torque is worth more than the headline power.
Is it too much for the gearbox?
The 9G-Tronic has its own torque limiter, which is precisely why we look at the gearbox software alongside the engine at these levels. Otherwise the box simply clips what you have paid for.
Does it help with towing?
That is one of the most common reasons people have a big diesel remapped. More torque lower down means less gear hunting and less effort on hills with a load behind you. It does not change your towing limits, which are a legal matter, not a power one.
What about the DPF and AdBlue on the diesels?
Both stay. Removing emissions equipment makes the vehicle illegal on the road and fails its MOT. If there is a fault we diagnose and repair it first.
How long does it take?
About two hours through the diagnostic port including a road test. We keep your original file so it can go back to standard at any time, and you can add dyno runs for the before-and-after graph.
