You know, with EVs and hybrids like that object these days, it’s rare to find a new internal combustion engine that’s truly cool and isn’t built for something inaccessible, like Bugatti’s naturally aspirated V16 or Lamborghini’s 10,000 rpm V8. But there may be a new contender for the most psychotic engine of 2026: Jeep’s Hurricane four-cylinder.
On paper, the Jeep’s four-banger doesn’t sound all that special—it’s a turbocharged 2.0-liter engine that makes 325 horsepower. You can yawn now. But it’s the technological ins and outs that make this car insane, and one of the most powerful four-cylinder engines in the world.
Allow me to explain.
Turbulent Jet Ignition
Photo by: Jeep
Let’s start with the main technology: Turbulent Jet Ignition (TJI). That’s Jeep’s marketing term for its pre-chamber combustion technology. Essentially, it’s Formula 1-derived combustion technology borrowed from the Maserati MC20’s Nettuno V6, but retuned for Jeep. He No a derivative of the old Maserati 2.0 which is no longer produced. These engines use a small space in the combustion chamber where the fuel-air mixture can be better mixed before ignition.
The way Jeep designed it is almost like a second form of fuel injection. The Hurricane 4 already uses both direct and port injection, with the direct injector handling most of the duties and the port injector supporting it. The pre-chamber uses an insert shaped like the tip of a fuel injector, with a specific spray pattern that helps distribute pre-mixed chamber air into the main combustion chamber.
TJI also uses twin-spark ignition, meaning there are two spark plugs per cylinder. The starting chamber has its own spark plug, which ignites the mixture before it is “sprayed” or effectively sucked into the combustion chamber during the power stroke. Then there is a second spark plug to help with unburned fuel or for other high load situations. But at its peak, the initial chamber helps Jeep engineers extract the absolute maximum amount of energy from a given fuel-air mixture.
Pre-chamber combustion is the secret to Jeep power output and fuel economy. In the heavy and aerodynamically draggy Grand Cherokee (relative to something like a Civic Type R), the Hurricane 4 achieves an EPA-estimated highway 27 miles per gallon, which is impressive.
Turbo Geometry Variables
Efficiency was the main function Jeep engineers drilled into my brain when showing me the Hurricane in person for the first time.
Internal combustion is inherently very inefficient. At its best, more than 50 percent of the energy produced by combustion is wasted through friction, pumping losses, and heat. Controlling energy loss is key to modern engine design, and turbochargers are a big contributor, taking one of the largest sources of energy loss and reusing it to produce more power.
The Hurricane 4 uses a variable geometry turbo (VGT), which sounds scary but is actually deceptively simple. There are arms and actuators that move a series of interconnected vanes in the turbocharger exhaust housing. The propellers help control the speed and amount of exhaust gases entering the turbo, which has a significant impact on power output.
The turbo itself is modest in size, with a 55 millimeter compressor wheel and a 50 millimeter turbine wheel. At its peak, it can supply enough airflow for 35 psi of boost, and looks like it was made by Stellantis itself. At least, I couldn’t find any other parts supplier’s stamp other than the Pierburg compressor wheel speed sensor.
Detail of the propeller actuator mechanism. Note the anti-rattle spring where the actuator arm meets the propeller arm.
Photo by: Chris Rosales / Motor1
VGT controls turbo speed, like a wastegate, but only in temporary situations. The biggest advantage of the VGT is its responsiveness—it can fire the turbo quickly when the throttle kicks in, but also regulate exhaust gas velocity to help efficiency during cruise.
There is also an additional emissions angle on the VGT. On cold starts, this helps warm up the catalytic converter more quickly and regulates overall exhaust gas energy. This is a great addition to the Hurricane 4 sandwich and is very rare on a petrol engine. Basically, it shares company with the 997 generation Porsche 911 GT2RS and 718 Cayman S.
Optimization
Detail of the electronic camera phase controller
Photo by: Chris Rosales / Motor1
Making all of that work requires a bit of support, which includes a few different technologies we’ve seen before, but it’s still worth mentioning. The intake camshaft uses an electric phaser, this is important because the ECU can move the camshaft at any time. Typically, camphasers are driven by oil pressure, which means the engine has to work to move them.
The electric phaser allows the Jeep to move the camshaft when the engine is off, which is critical for smooth start/stop transitions. By moving the cam, Jeep can effectively “decompress” the cylinder, helping with smooth start-up. This also gives the Jeep a wider intake cam adjustability, which offers greater combustion efficiency. The Storm also runs on the Miller cycle, which keeps the intake valve open longer, helping further fuel-air mixing.
Then, compressed air from the turbo is cooled by a relatively small water-to-air intercooler, although Jeep says most of the work is done by a front-mounted heat exchanger, which keeps the main intercooler small.
Photo by: Chris Rosales / Motor1
Looking at the details around the engine, it is very modern. The block is made of aluminum and has extensive webbing, but the materials used are minimal. Visually it is similar to the highly subtractive BMW B48 / B58 engines in terms of construction, but it is difficult to tell the difference without the cuts.
The edge of the block—essentially the part of the block that extends below the centerline of the crank—is also deep, indicating a lot of strength at the bottom end. Although I’m not sure what holds the crankshaft in the block, whether it’s the separate main cap or the bed plate.
Photo by: Chris Rosales / Motor1
Storm 4 is, overall, an interesting entry. I sampled it in the Grand Cherokee for a bit and found it surprisingly willing to take on the big SUV. It does feel burdened, but the power is good once the engine can reach a certain RPM. Turbo lag is minimal, but the engine clearly has a mid-to-high biased powerband. This is the danger of using a small capacity engine.
I would hope that this engine could be used in a sports sedan. Or maybe even a sports car. The amount of technology Jeep has put into this engine as a base powertrain is impressive, and it’s definitely pushing the boundaries harder than any other Jeep engine ever made.
Who knows?
