The Mercedes-AMG SL 65 is a peculiar car for aftermarket tuners. Like the BMW M6, the AMG SL 65 isn’t small enough to provide room for enormous tuning potential, but it’s also not up-market enough to not need one in the first place. That’s likely one of the reasons why there aren’t that many tuners who work on the AMG SL 65. Not that it’s the tuner’s fault because if there’s not enough there to work on, why even bother in the first place? Fortunately, a tuner like Vath doesn’t preoccupy itself with asking these types of questions. it just goes ahead and does it. And that's exactly what we have here with this new tuning program for the AMG SL 65 that gives the performance convertible a higher output of 672 horsepower and 847 pound-feet of torque.

The power figures are nice, but the real treats of this particular tuning program from Vath are the complementary upgrades on the convertible. After all, it’s not enough to have an engine upgrade without working on other sections of the AMG SL 65 that are directly affected by the improved power and performance. Go to the tuner’s website you’ll see a comprehensive tuning kit that also includes upgrades to the car’s exterior, interior, suspension, and wheels.

In a lot of ways, this is what you can expect from a tuner like Vath, which specializes on developing programs for Mercedes models. A quick look at its portfolio reveals that the German tuner has kits available for a handful of Mercedes models like the CLA-Class, E-Class, and S-Class to go with their AMG counterparts.

There’s a lot to get through with Vath’s new program for the AMG SL 65 and for what it’s worth, the upgrades are what you expect to get from a shop like this. That’s what happens when you have a company that has literally spent years of its existence fine-tuning its abilities in creating programs for models that can be filed under Mercedes.

Continue after the jump to read more about the Mercedes-AMG SL 65 by Vath.

Exterior

The exterior modifications on the AMG SL 65 aren’t extensive relative to what we’re used to from Vath. That said, they’re not completely useless either because al the new parts and components of Vtah’s aero kit comes with their own specific purposes. Taking from some supplementary details on Vath’s own website, we learned that the program comes with an aerodynamic kit made up of carbon fiber parts for the front spoiler and rear diffuser with the latter only eligible for AMG SL 65 models that come with the AMG Sports package. A new trunk lip spoiler is also being offered, although that one is made from PU-Rim. The other important upgrade to the AMG SL 65’s exterior is the new set of 20-inch, titanium-colored forged wheels that Vath is offering a number of sizes, ranging from 8.5 J x 20 all the way up to 10.5 J x 20.

The dearth of tuning kits for cars like the AMG SL 65 means that we’re going to have go outside Mercedes to find a suitable tuning comparison. Fortunately, the AMG SL 65’s biggest rival - the BMW M6 - also was the recipient of its own aftermarket program from G-Power. In this kit, G-Power’s exterior upgrade for the M6 only revolves around its own set of 21-inch, ultra-light, aircraft-grade aluminum Hurricane RR wheels. There’s admittedly not much to compare here but it is worth noting that the M6 looks a lot better with those 21s than the AMG SL 65 does with the 20s that Vath provided for it.

Interior

Give Vath credit for this: when other tuners are openly ignoring the interiors of the cars they develop programs for, Vath isn’t taking any of those shortcuts. Sure, the upgrades are reasonably simple -- black carbon refinements for the two-door trims, center console, and ashtray cover -- but they’re there, which is more than what you can say for G-Power’s interior upgrade for the BMW M6, which really amounts to nothing. At least for this section, the fact that there are aftermarket options for AMG SL 65’s interior that are available from Vath gives the Merc tuner the distinct edge.

Drivetrain

Here’s where it really gets interesting for Vath. The press release reveals an engine program that includes adjustments to the water/heat exchanger and the high flow air filter on the car’s 6.0-liter bi-turbo V-12 engine to go with software and electronic upgrades. The result is a new output of 690 horsepower and 847 pound-feet of torque, although the latter has been limited to the “standard” 737 pound-feet of torque. That horsepower figure represents an increase of 69 ponies over the standard output and is good enough to attain a top speed of 202 mph. There’s a catch though.

A quick look at Vath’s website also reveals a more powerful “V65RS” program that nets a peak output of 745 horsepower and the same “attainable” 847 pound-feet of torque that’s been limited to the standard 737 pound-feet of torque figure. According to Vath, the V65RS program includes the usual suspects from the previous upgrade and adds high-performance cooling systems for the engine and transmission. Not only does this kit attain a higher output, it also improves the AMG SL 65’s top speed to an impressive 224 mph.

Regardless of the upgrade, Vath is also offering its own valve-control muffler exhaust system that offers three different sound levels and wireless remote control.

By comparison, G-Power’s kit for the M6 nets similar aftermarket numbers -- 740 horsepower and 720 pound-feet of torque -- that the tuner achieved courtesy of its Bi-Tronik 2 tuning module. These upgrades help the M6 post a 0-to-124-mph time of 10.7 seconds to go with a top speed of 186 mph.

Chassis

The standard ABC sport chassis (Active Body Control) is lowered to a tight, sporty level. The chassis is still pleasant and comfortable to drive on the first level. Even the handling in curves has been significantly improved. The visual impression of the vehicle's dynamic has been increased dramatically. The chassis modification is available for a moderate 1,450 Euro plus 450 Euro installation including axle alignment.

Pricing

Depending on what engine program you get, the pricing for the entire program will vary. Fortunately, Vath was nice enough to break down the price figures of each of the upgrades, which you can see in the table below.

Competition

BMW M6 by G-Power

The aforementioned BMW M6 program from G-Power can be considered a suitable rival to Vath’s kit for the AMG SL 65 in part because of the massive power increase it provides. Remember, the M6 “only” uses a 4.4-liter twin-turbo V-8 engine compared to the much bigger 6.0-liter V-12 of the AMG SL 65. Still, even with the “smaller” engine, G-Power was able to coax out an impressive 740 horsepower and 720 pound-feet of torque out of that V-8 engine. That goes to show how potent G-Power’s Bi-Tronik 2 tuning module is. The top speed may be limited to just 186 mph, but rest assured, this M6 is a blitz off the block, capable even of sprinting from 0 to 124 mph in just 10.7 seconds.

Read the full review here.

Conclusion

To be fair to other tuners, Vath isn't the only one that has a program for the AMG SL 65. The thing is though that most other tuners don't offer a kit as comprehensive as the one Vath has for high-performance Mercedes convertible. Some might rival it in terms of having more power, but Vath is as good a tuner as you can find if you're in the market for an aftermarket program for your AMG SL 65. That's a reputation it has earned and has maintained over the years.