Jeep Trackhawk Engine

Michael Febbo
Mar 5, 2021

2018 Jeep Grand Cherokee Trackhawk

The Trackhawk offers near supercar performance in a more usable package. That’s thanks to the Hellcat Hemi engine, a 707 hp monster & modern marvel of engineering.

Your responsible-adult mind says you need the utility of an SUV but your more childish car-enthusiast mind says what you really want is a muscle car. Luckily, several car manufacturers employ the kind of product planners that “get you.” One of the best is Chrysler, which has rooted around in the minds of car enthusiasts and plucked out the data necessary to provide a whole line of vehicles that satisfy our needs and our wants. The 707 hp Jeep Grand Cherokee Trackhawk, with the Hellcat V8 engine under the hood, is the perfect example.

In 2015, Chrysler’s Street and Racing Technology (SRT) division launched the Hellcat-powered Dodge Challenger and Charger as halo products for its already musclebound line of Hemi V8 powered cars. The supercharged coupe and sedan boasted 707 hp and 650 lb-ft of torque. With the success of these vehicles, it made sense to offer the Hellcat engine in other Chrysler platforms; the Jeep Grand Cherokee was an obvious choice.

Unlike the rear-wheel-drive Challenger and Charger, the Grand Cherokee SRT remained all-wheel drive, meaning it could better utilize all that V8 torque for acceleration rather than tire smoke. Whether that’s a positive or negative for you says a lot about your personality and car-buying preferences.

The first year of the Jeep Grand Cherokee Trackhawk with the Hellcat Hemi engine was 2018, and not much has changed between then and the current 2021 model year.

What is a Hemi Engine?

Strictly speaking, a hemi (non-trademarked) refers to an engine with hemispherical-shaped combustion chambers. Early engines used several different types of combustion chamber designs that were anything from completely flat to wedges and even hearts.

The shape of the combustion chamber determines the size and placement of the valves. Most people don’t give it much thought, but how air enters the combustion chamber plays an important role in the engine’s efficiency. For performance, you want as much air as possible to get into each cylinder; that requires high velocity. But, a head designed just for maximum airflow, might not operate well at anything but full throttle.

Engineers also want to control where the air is flowing as it enters the combustion chamber. Directing the airflow going in, controls the shape of the actual combustion event – the air and fuel burning, which is what pushes the piston down. You can throw as much fuel as you want into the process, but if it isn’t all burned before being pumped out the exhaust valve, you’re just throwing away gas and by extension, power.

The hemispherical head allows for intake and exhaust valves to be positioned opposing one another in the chamber. This allows the intake air and fuel mixture to swirl around in the cylinder increasing how fast it burns. The hemisphere as a shape, also the best surface area to volume ratio possible. This means the least amount of energy is absorbed into the head, instead of being used to push the piston down.

Powering the 2021 Jeep Grand Cherokee Trackhawk is a supercharged 6.2-liter V-8 engine delivering 707 horsepower and 645 lb.-ft. of torque

History of the Hemi

The first hemispherical car engines date back to the beginning of the 1900s. Two car companies, Welch and Pipe, both built hemispherical engines between 1903 and 1905, which was first is a matter of debate.

Chrysler began using the term to describe its Firepower 8 and 6-cylinder engines in the 1950s, it wasn’t until 1964 when it leaned into Hemi for marketing purposes. Originally developed for NASCAR, Richard Petty used an A-864 Hemi engine to win the 1964 Daytona 500. In 1965, it was banned from several racing series because it wasn’t available in production cars. Chrysler began selling a few low production cars with the 426 Hemi for drag racing, but in 1966, the “street” Hemi became widely available as an optional engine in mainstream production cars. By 1971, the age of muscle cars had ended and the second generation Hemi went with it.

In 2002, the Hemi returned as 5.7L pushrod V8, with the name stylized in all caps “HEMI,” in Dodge Ram trucks. By 2005, a whole line of Chrysler rear-wheel-drive cars and all-wheel or 4-wheel drive SUVs were also available with a Hemi. In 2005, a 6.1 L version was produced for the SRT-8 line of vehicles. This was the first time we saw an SRT version of the Jeep Grand Cherokee and the first time a Jeep product gave up just about all of its off-road ability for on-road performance.

Although the SRT vehicles would get an even larger version of the Hemi, the 6.4-liter 392 Apache V8 engine, Chrysler knew it needed more. With several manufacturers making smaller and more efficient turbocharged engines over-powering and worse, over-torquing the Hemi, it was time for a game-changer. Named after a World War II fighter aircraft, the Hellcat Hemi V8 debuted in 2014 with outrageous power numbers.

Trackhawk V8 Engine: Special on the Inside

When rumors of the Hellcat began circulating, journalistic outlets all over the internet claimed inside sources had told them SRT had just bolted a supercharger to the top of a Hemi and were squeezing out “over 600 horsepower.” When the actual specs of the engine were officially revealed, those sources weren’t exactly lying, but they hadn’t been telling the whole truth either.

The first thing was obviously the power rating. While 707 hp is indeed “over 600 hp” but was certainly underselling it. The second part about “just bolting a supercharger on a Hemi” was also selling short the amount of work the SRT engineers undertook to get that unprecedented amount of power in a reliable, daily-drivable package.

The Hellcat engine starts with the 6.4-liter Apache block, but it only shares 9%, by cost not count, of its total components with the Hemi 392 found in other SRT products. To start, the Hellcat is a 6.2-liter. The slight loss of displacement comes from a shortened stroke from 94.6 mm to 91.0 mm. The bore is shared at 103.9 mm. Shortening the stroke accomplishes a few different things, all related to the greater strength of components or less stress on the engine. First, decreasing stroke shortens the distance of the crank journals to main bearing journals, decreasing the amount of torque the crank has to endure. Second, it changes the angle of the connecting rod decreasing side loading on the piston inside the cylinder.

Both the 6.4L and 6.2L Hellcat use forged crankshafts. The Hellcat crankshaft is stronger and uses induction-hardened bearing journals. The Five main bearings are held in place with a total of 20 bolts. The rods are powder forged steel while the pistons are forged aluminum and the piston pins are coated with a carbon coating. The diamond-like coating allows for greater load-carrying while also reducing friction and wear.

Hellcat Hemi V8: Special above the Block

The Hellcat uses aluminum heads, with shared architecture with the Apache. The 356-T6 aluminum alloy used for the Hellcat is stronger and offers better heat dissipating properties. The single camshaft, which obviously sits between the two banks of the pushrod V8, is similar to that of the Apache. It uses a variable cam gear to phase the cam-timing, but valve lift is fixed.

The real difference with the Hellcat is the IHI built supercharger sitting in the valley of the V8. Even with an aluminum housing and rotors, the twin-screw type 2.4-liter unit still weighs 80-pounds. Boost is controlled with an electrically controlled bypass valve, which allows a maximum of 11.6 psi of pressure. At maximum boost, it can move 30,000 liters of air per minute but also consumes 80 hp in the process. A small tradeoff for the 707 hp delivered at 6,000 RPM and the 645 lb-ft of torque, which peaks at 4,800 RPM.

Is the Trackhawk’s Hellcat Engine Reliable?

Determining any vehicle’s reliability is never a trivial task. While some people head to internet forums, these represent a microcosm inside a much larger owner group. When it seems like everyone is having the same problem with a vehicle, it may only be a couple of dozen owners out of tens of thousands.

Looking at organizations like J.D. Power, who issue reliability ratings can be a decent start. The Grand Cherokee Trackhawk is listed as an 81 out of a possible 100, so a B- on the academic scale.

If we navigate over the National Traffic and Safety Administration, or NHTSA for short, we can find owner complaints, manufacturer communications and recalls. The complaints can be tedious to wade through, but they will give you an explanation of the problem and the number of owners who have reported the problem. The Trackhawk has multiple complaints, not at all uncommon, but most engine complaints seem to be single issues.

In manufacturer communications, the engine-related communications seem to cover multiple vehicles in the Chrysler Group and all have fixes listed. At the time of writing this, there were no recalls listed for the Trackhawk’s Hellcat engine.

It may not be reliability-related, but if you are looking at cost of ownership, you may want to do some quick calculations on what it will cost to keep the tank full on a Trackhawk. In the EPA’s normal test cycle, driven like every other car on the road, the Hellcat achieved 11 MPG in city driving, 17 MPG on the highway, and 13 MPG combined. The average combined fuel economy for its class is 19 MPG.

Is the Trackhawk’s Hellcat Engine Any Good?

We have to judge the Hellcat in two different ways; objectively and subjectively. You can ask a dietician if a half-pound bacon double cheeseburger is “good,” and objectively they will tell you no. If they’re human, they will give you an enthusiastic thumbs up. The Hellcat is the fully one-pound, extra bacon, extra cheese, quadruple burger of the car world.

Even objectively, we have to appreciate the fact that Chrysler is able to deliver over 700 horsepower in a package that is drivable on a daily basis and offers a factory warranty. Developing those big power numbers automatically includes the challenges of handling huge forces on components and managing an enormous amount of heat.

Objectively, it is very easy to look at power and torque numbers compared to displacement and maybe not be all that impressed. The Germans are making much smaller, turbocharged V8s that not only make more torque but make it at far lower RPM. They also deliver better fuel economy and are just as usable on a daily basis. Both Lamborghini and Ferrari have naturally aspirated 6.5L V12s that deliver more horsepower and torque; the least expensive of these cars is roughly the price of three and a half Trackhawks.

Subjectively, however, this engine is not only good, it’s truly remarkable. Stats on paper never show the whole picture of the experience. Most of the modern turbocharged engines don’t have the throttle response or linearity you get from a big supercharged V8. Turbochargers often have an all-or-nothing response, superchargers on the other hand can dole out power in measured increments that almost feel like a naturally aspirated engine. From the response to the feel to the sound, there isn’t another experience that matches the Hellcat for sale today. Sadly, the ridiculously bad fuel economy and emissions, which are impossible to justify objectively or subjectively, means the Hellcat’s days are ultimately numbered.

2020 Jeep Grand Cherokee Trackhawk

Jeep Grand Cherokee Trackhawk & Hellcat Engine FAQ

  • When did the Jeep Grand Trackhawk come out?
    • The first model year for the Trackhawk was 2018
  • Is the Trackhawk all-wheel drive?
    • Yes, it uses a specialized AWD system shared with the SRT
  • Can a Trackhawk be used for towing?
    • Yes, it can tow up to 7,200-pounds
  • Who makes the Hellcat’s supercharger?
    • The twin-screw supercharger is manufactured by IHI in Shelbyville, Illinois
  • Where are the Hellcat engines built?
    • All Hellcat engines are built in Saltillo, Mexico
  • Why does the Trackhawk’s engine make 5 lb-ft less torque than other Hellcats?
    • SRT claims the slight drop in torque is due to the Trackhawk’s exhaust

Photos: Jeep

Owner Reviews

accountCircle Eric V on June 22, 2021
Best high performance SUV of the class.
I had previous experience with jeep. Products in the past had a generally negative opinion. However, the influence of the Daimler association appears to have really brought the quality of the vehicles to an exceptional level. This quality, in terms of fit and finish, married with the performance of the dodge hemi engine has produced a truest exceptional vehicle in terms of quality and performance. The ride is comfortable when in touring mode and appropriately aggressive when in sport or track mode. If as a consumer you are looking for performance I would propose that it is going to be hard to equal a 5,500 lb SUV that can pull a 3.4 second 0-60 time. As some background I have owned and do own high performance vehicles (mustang gt500 and gt350, challenger widebody scat pack, BMW x5 with m package and sport, corvette) and the jeep ranks right at the top of that list,
accountCircle Cid A on August 28, 2021
For the adrenaline junkie who is looking for something comfortable.
The 2 years that I've had my vehicle I haven't encountered any problems with it. Its a fast SUV with the comfort for a family of 4-5. So if you are looking for both of those features this vehicle might be for you. It has different modes you can drive in depending on weather conditions/or what you are doing. It does have features like detecting sudden stops in front of you, parking detention, windshield detection etc. My favorite part is the interior. Red leather seats, seat warmers front and back. It's a really good SUV.
accountCircle Kui L on March 31, 2021
Fast comfortable and useful.
Its fast and the supercharger is loud. Also good for everyday driving. It's very spacious and it performs very well. Its has around 700 horsepower and its smooth and quiet for normal driving but if needed can drive super fast. The looks are also very nice and it's comfortable. Gas mileage is decent but if driving fast can use a lot of fuel.
accountCircle Tasha M on April 18, 2021
Awesome jeep, great for family size group and traveling.
So far no problems, it is been running strong and so comfy for long drive. Plenty of leg room for tall people and the back has plenty of space for grocery or anything you might buy. The technical stuff is not as far ahead since it is a couple years old. It does eat put gas faster than some but it is very reliable.
accountCircle Brandon B on June 9, 2021
Summary about the Jeep Cherokee.
It's an amazing vehicle. It has the horse power I need and more. Also its a luxury car as well as sport. Very happy about my purchase, and would recommend anyone that could afford one to get one. Also it has plenty of room for sound systems if one is installed into the car.
accountCircle Daylo B on July 27, 2021
Trackhawk 2020 grand Cherokee is a sports SUV and a luxury SUV.
My 2020 trackhawk has zero problems. The performance is amazing, very easy to drive. The 2020 jeep grand Cherokee trackhawk is very reliable and comfortable. New added features for chairs, air/heat, radio and navigation. The trackhawk is fast and casual for all occasions.
accountCircle Davion T on August 20, 2021
It has enough cup holders for 5 people.
It is very comfy! And the steering wheel is easy to control! The radio is perfect and it's easy to hear. And the seats are very comfy and smooth. The trunk is very spacious. The car is big enough for 5 passengers. And it has a place for a spare tire which is awesome!
accountCircle Rebecca H on April 8, 2021
Not your average SUV- jeep trackhawk.
My 2018 jeep trackhawk is a dream vehicle. Plenty of room and speed to give you a thrill when you want to feel the power. 707 horsepower and full of torque. Not your average “mom car”. From a dig, this vehicle will launched past most other performance vehicles.
avatar Michael Febbo
Michael Febbo is an award-winning writer and editor with over 15 years of experience in automotive journalism. Upon graduation with a Mechanical Engineering degree from the University of Nevada Las Vegas, he tried a variety of jobs in the auto industry, including selling BMWs and working at tuning shops. He eventually embarked on a career as an auto journalist. After a few years as a freelancer and writing for a European car magazine, Febbo joined the staff at Motor Trend, where he track-tested cars and did high-profile auto comparisons. After four years at Motor Trend, he was offered an Editor-in-Chief gig at a European car magazine that led to winning back-to-back Western Publishing Association Awards. He has also written for Luftgekuhlt and Porsche Motorsports.
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