It has been two years since Mercedes stopped production for the SLS AMG. It doesn’t seem that long ago, but with the arrival of the AMG GTand its more powerful brothers, the AMG GT S and the AMG GT R, the SLS AMG has ascended into its rightful place as a modern-day classic. That status will live on for a long time and it’s a big reason why there are still tuners out there who are still building programs for the departed supercar. One of these tuners is RFK Tuning, which went out of its way to build a tuning kit that provided upgrades to various sections of the car, including the 6.3-liter V-8 engine that now puts out 605 horsepower and 498 pound-feet of torque.

The tuner put in a lot of work on this program, even going so far as to dress the SLS AMG up in a fancy body wrap. It also took out the supercar’s standard wheels and fitted a newer and admittedly fancier set. But the engine upgrade is the real treat here, not because of the modest power gains, but because RFK somehow managed to bring the car’s top speed north of 200 mph.

It’s not a mind-blowing program, but it is a nice one that should fit seamlessly into the SLS AMG’s flamboyant character. Even if it’s been two years since the Mercedes supercar was last seen in dealerships, it’s nice to know that there are still tuners like RFK Tuning that are willing to work on giving it the kind of aftermarket love it so richly deserves.

Continue after the jump to read the full review.

2016 Mercedes SLS AMG By RK Tuning

Specifications
  • Make: Array
  • Model: 2016 Mercedes SLS AMG By RK Tuning
  • [do not use] Vehicle Model: Array
Pros
Cons

Exterior

RFK Tuning’s first order of business was to wrap the SLS AMG in a Mirror Chrome Red foil wrap. The tuner also dressed up the model lettering, fuel cap, and the three-pointed star in contrasting gloss black foil. Rounding out the exterior modifications are a new set of 20-inch E1 10-spoke mono block alloy wheels from Elegance Wheels, RFK’s in-house wheels label. The wheels are shod in 265/30R20 and 295/30R20 tires in the front and rear respectively.

Interior

Interior upgrades are non-existent as RFK Tuning preferred to keep the cabin of the SLS AMG in standard configuration.

Drivetrain

Note: Engine from 2014 Mercedes SLS AMG GT Final Edition shown here.

At the heart of RFK Tuning’s program for the Mercedes supercar is an engine upgrade that helps increase the output of the SLS AMG’s 6.3-liter V-8 engine. The tuner didn’t specify the kind of program it gave to the Merc supercar, but it did say that the final product is an output of 605 horsepower and 498 pound-feet of torque. It’s not a significant bump in power considering that the standard output of the V-8 is 571 horses and 479 pound-feet of torque, but is good enough to improve the supercar’s top speed to 208 mph, 11 mph higher than the standard model.

Chassis and Suspension

To complement the engine upgrade, RFK Tuning fave the SLS AMG a specially valved KW Variant 3 coilover suspension kit that not only features adjustable ride height, but also comes with damper bounce and rebound control.

Pricing

Not surprisingly, RFK Tuning has not made the program’s pricing public, which obviously leads me to making the point of contacting the tuner directly in the event you’re interested in giving your SLS AMG a belated tuning upgrade.

Competition

Mercedes SLS AMG Roadster by TAg Motorsports

The Mercedes SLS AMG’s production ended in 2014 so most tuning programs of the supercar – and there were a lot! – were made during that time as well. But there is another tuner that just presented its own program for the since departed supercar, albeit one for the SLS AMG Roadster. That tuner is Tag Motorsports, which presented a punchy engine upgrade package back in June 2016 that netted 620 horsepower and 522 pound-feet of torque. Tag was able to achieve that output by giving the SLS AMG Roadster’s 6.3-liter V-8 engine a RENNtech’s R2 performance kit that was made up of an ECU upgrade, stainless steel long tube headers with 200-cell cats, and an X-Pipe. No performance numbers were given, but considering the details of the performance kit, a top speed of over 200 mph for the SLS AMG Roadster was reasonable.

Read our full review here.

Mercedes SLS AMG by Kleeman

For those who are interested in something from the SLS AMG’s time period, one of the most recent ones that was developed came from Danish Mercedes tuner Kleeman. The program was presented back in 2013 and featured an engine upgrade that came with a new supercharger, polished-stainless-steel exhaust system with a bolt-on cat-back system, a dual mid-muffler, an "X" pipe, and a remote-control exhaust flapper. The result of that program blows what RFK Tuning and Tag Motorsports did to the SLS AMG as Kleeman was able to generate a whopping 770 horsepower and 623 pound-feet of torque out of the SLS AMG’s V-8 engine. Top speed also increased to 221 mph, which shows you how mental that program really was.

Conclusion

A car like the Mercedes SLS AMG is timeless so if you have one, better take good care of it. I’m not going to tell you what to do with it, but if it’s the tuning route you prefer, I’m not going to be mad about it. To be clear, there are still a lot of tuners who would love to work on the SLS AMG and that list obviously includes RFK Tuning. It’s not the biggest and baddest kit for the SLS AMG, but it does accomplish its objective of bringing new life to the supercar, both in terms of the cosmetic body wraps and the engine upgrade package.