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We tried out Hennessey’s 850 horsepower Mustang, and we have thoughts

We go hands on with the H850 Dark Horse

The Hennessey H850 Mustang Dark Horse
Dave McQuilling / The Manual

The Ford Mustang Dark Horse is one of the most powerful vehicles the company produces and also one of the hardest to tune. With 500 horsepower coming courtesy of a naturally aspirated V8 and a stripped-down interior created with racing in mind, Ford’s premier muscle car comes ready to take on the track or drag strip. But for some people, that 500 horsepower isn’t enough, and the Dark Horse needs a bit more oomph. Luckily, there are a couple of options available, so you can get that without having to alter the Mustang yourself.

This is where John Hennessey, a man who made his name getting more out of already powerful cars, comes in. For a shade under $25,000, Hennessey will supercharge your Dark Horse, which bumps the vehicle’s horsepower up to a staggering 850. That’s more than a Ferrari Daytona SP3 or a Koenigsegg CCR. It’s 232 more than the legendary McLaren F1.

We were lucky enough to try out one of Hennessey’s supercharged Mustangs while visiting the company’s shop down in Sealy, Texas. Here’s what we found.

There’s a lot of overlap

Hennessey H850 Interior

The H850 is predominantly a performance package. So, ignoring what happens when you get your foot down, the “H850” badges on the wings, and the occasional additional bit of detail, the experience is pretty much the same.

For those who are unaware, the Dark Horse is currently the most expensive Mustang trim, but it lacks the comfort features of the GT trim. This has nothing to do with Ford’s profit margins and is more in line with the Dark Horse’s ethos. It’s a racing model, and performance is paramount when it comes to race cars. Infotainment, air conditioning, and other comfort aspects that did make it into the Dark Horse remain the same.

In addition to the weight-shedding, the other performance aspects of the Dark Horse carry over. Like the larger wing and staggered wheel sizes. Hennessey has picked the perfect trim for their package here, as they don’t need to worry about tweaking too much outside of the engine bay.

Other details carry over, too. The automatic rev-matching manual Mustangs have featured for the last few years is still there when Hennessey’s performance package is fitted. This in itself takes one of the harder parts of performance driving with a stick shift out of your hands completely — allowing you to concentrate on the performance increase and get more out of the car at a lower skill level. It’s also a great reason to opt for a manual transmission when speccing out your vehicle.

The sound is surprisingly good

Hennessey H850 Mustang Engine Bay

In this day and age, it’s hard to beat the throaty sound of a naturally aspirated % liter V8. In fact, it’s fair to argue that the aggressive chorus emanating from under the hood is as much a part of a Mustang’s character as anything.

So when you remove the natural aspiration aspect and slap on a hefty supercharger, there’s always going to be the worry that you’ll lose a little bit of the vehicle’s soul in the process. With the H850, this isn’t really the case. Yes, the sound isn’t quite the same, but it is still very loud and very aggressive. It ties in with the increased performance, and when you have the hammer down, it’s pretty much just as exhilarating an experience as you would expect from one of the world’s most powerful muscle cars. The V8’s sound stands out best when you’re applying a good amount of throttle, and it still sounds like some kind of rampaging beast when you’re doing that in the H850.

You can take it to the track, but it may be one for the dragstrip

The Hennessey H850 Mustang Front
Dave McQuilling / The Manual

As you may expect, where the extra horsepower really pays off is on a long, straight piece of road like a runway or drag strip. Here, you can really get the hammer down and feel the pull of an excessively powerful muscle car. In short, if you like the feel of acceleration then there are few things more potent than the Mustang H850. It will throw you back in your seat as it serenades you all the way down a stretch of road. Just make sure said stretch of road is clear because the boosted Stang will have you ripping past speed limits before you know what’s going on.

With that being said, there is another use for the supercharged Mustang. The extra horsepower on offer makes it pretty easy to get the back wheels spinning. So, if you have a thing for donuts, drifting, or burnouts, then you’re going to have a far easier time indulging in your passions with Hennessey’s performance package installed. Not that it’s hard to do all of that with the 500 horsepower Ford gives you to start with.

It’s a bit of a bargain at $25,000

Hennessey H850 Side
Dave McQuilling / The Manual

While the supercharged Mustang may be a bit pricey when you factor in the $25,000, the cost of the base vehicle, and any additional money you may spend, it’s a bit of a bargain should you already own a Venom F5. It boosts the horsepower you will have available by 70%, which is not insignificant. You’ll also get a Hennessey graphics package, which adds to the air of exclusivity around the vehicle. Hennessey is sticking to 200-ish units per year, so you may struggle to get the upgrade even if you have the cash available.

If you can get it done, you’ll end up with one of the most exclusive yet financially accessible vehicles on the road. It may rival the upcoming GTD in terms of power and may even be able to beat Ford’s upcoming ultra-exclusive hypercar when it comes to speed. In short, I’ve seen worse options at the price, and the upgrade is something you should totally book your vehicle up for if it is in any way an option.

Dave McQuilling
Dave has spent pretty much his entire career as a journalist; this has included jobs at newspapers, TV stations, on the…
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