Hennessey is known for a lot of things in the auto industry, one of which is its ability to develop insane tuning programs for American performance cars. The Ford Mustang GT counts itself in this group and, while Hennessey has created past programs for the Ford muscle car in the past, this one carries a unique flavor because it’s been dubbed the 25th Anniversary Edition HPE800 Mustang GT to celebrate the company’s 25 years of existence. It’s a fitting name since this limited edition Mustang carries a lot of the characteristics of the full Hennessey tuning experience, highlighted by an increase in output to 804 horsepower and 648 pound-feet of torque.

By any tuning metric, that output is astounding, and more so for a car whose engine “only” tops out at 435 ponies and 400 pound-feet of torque. But that’s Hennessey for you. The American tuner doesn’t work on programs that offer modest gains; it swings for the fences. The 25th Anniversary Edition HPE800 Mustang is proof of that.

In addition to the engine tune, the limited edition program also comes with a useful set of aerodynamic components, a flashy set of wheels, and a modest interior upgrade that ironically comes with a few not-so-modest reminders of the car’s exclusivity.

The only downside to this program is that it’s limited to just 25 units and, as of now, there’s no telling how many of them are still available. Better be quick about it if you’re interested. Give Hennessey a ring or you might be left out on acquiring this alluring piece of tuning brilliance for the now 25-year old tuning wizard.

Continue reading to learn more about the Ford Mustang GT By Hennessey.

2016 Ford Mustang GT 25th Anniversary HPE800 Edition By Hennessey

Specifications
  • Make: Array
  • Model: 2016 Ford Mustang GT 25th Anniversary HPE800 Edition By Hennessey
  • Engine/Motor: V8
  • Horsepower: 804
  • Torque: 648
  • [do not use] Vehicle Model: Array
Pros
Cons

Exterior

Hennessey’s aerodynamic upgrades for the limited edition 25th Anniversary HPE Mustang GT is limited to a front splitter, side sills, and rear lip spoiler. All three components are made from carbon fiber and fit in nicely with the stealthy black exterior paint of the muscle car. Exterior badges, including one that denotes the car’s 25th Anniversary “status” make up the cosmetic upgrades on the exterior. Finally, the tuner is also offering a new set of its very own 20-inch H10 lightweight wheels shod in Michelin Pilot Super Sport tires.

Interior

There’s not a lot of work that went into upgrading the ‘Stang’s interior, but Hennessey did add new florist and embroidered headrests to at least create some differentiation from the standard Mustang GT. Speaking of unique, the cabin also features a serial-numbered plaque denoting which of the 25 models a particular car is. Obviously, that numbering goes from “1 of 25” to “25 of 25.”

Drivetrain

The special edition Mustang GT has been described as a ’Stang on ‘roids and, considering the kind of upgrades Hennessey put into the car’s 5.0-liter V-8 engine, it might as well be drug-tested. All joking aside, the upgrades are incredible and it starts with a 2.9-liter supercharger that was strapped into the V-8. From there, Hennessey attached a high-induction intake system and a new, axle-back exhaust system. The tuner also upgraded the fuel injectors, fuel pump, and coilpack covers before finishing it off with some careful tuning of the engine management system. The result is an output of 804 horsepower and 648 pound-feet of torque, a massive increase of 369 horses and 248 pound-feet of twist from the Mustang GT’s standard output of 435 horsepower and 400 pound-feet of torque.

As impressive as the supercar-worthy power output is, the performance translation is just as impressive, maybe even more. With the modifications in tow, the 25th Anniversary HPE800 Mustang GT is now capable of sprinting from 0 to 60 mph in just 3.1 seconds and can hit the quarter-mile in 10.7 seconds at 133 mph. Top speed has also been increased to 208 mph.

Chassis and Suspension

To accommodate the massive engine upgrade, Hennessey is offering a KW Variant 3 lowered suspension upgrade.

Prices

Hennessey didn’t announce the pricing details for the 25th Anniversary HPE800 Mustang GT but, needless to say, those interested in it should be prepared to spend a small fortune for the car. As I said, only 25 units will be made and, given the nature of the program, expect all 25 units to be accounted for in no time. The best thing to do is contact Hennessey directly and ask for the limited edition car’s availability. In the event that some are still available, prepare to make a quick decision on whether a reservation is in order or not.

Competition

Ford Mustang GT 820 By Geiger Cars

There are a lot of similarities between Hennessey’s HPE800 program for the Mustang GT and Geiger Cars’ own GT 820 kit for the same muscle car. For one, both programs are highlighted by the addition of a 2.9-liter supercharger. In Geiger’s case, the tuner also added a new crankshaft, forged pistons, steel connecting rods, a cold air intake system, and a stainless steel sports exhaust system. There are slight differences in the way both tuners approached their respective programs, but the results are similar as Geiger was able to bring out 820 horsepower and 560 pound-feet of torque out of the ‘Stang GT’s 5.0-liter V-8 engine. The tuner didn’t announce any performance numbers, but you can expect the GT 820 Mustang to sprint from 0 to 60 mph in around three seconds to go with a top speed in excess of 200 mph, assuming the tuner lifted the engine’s speed limiter.

Read our full review here.

Ford Mustang TrakPak By Roush Performance

The Mustang programs that Hennessey and Geiger Cars developed for the Mustang GT are impressive, but a case could be made that Roush Performance just made one that’s a little better than both tuning kits. The tuner accomplished that by creating a three-stage engine modification program that tops out at 850 horsepower. Oh, and yes a supercharger kit is also in the mix, as are upgrades to the fuel injectors and fuel pump. Roush wasn’t clear on how its upgrades translate to performance, but given that 850 horsepower is available, these numbers could amount to a sub-three-second sprint to 60 mph and a top speed that easily eclipses 200 mph.

Read our full review here.

Conclusion

The Ford Mustang GT is already a car that’s worthy of acclaim. What really separates this tuning program from others of its ilk is the fact that Hennessey, one of the best American tuners in the business, combined it as a special edition model with very limited numbers. That adds to the appeal of the car, especially when its billing is tied into the tuner’s 25th anniversary. Other programs may be better, but as far as exclusivity is concerned, Hennessey’s 25th Anniversary HPE800 Mustang GT is as good as it’s going to get.