Jeep's New Hurricane 4 Engine Is Insane!

TL;DR

Jeep's Hurricane 4 uses F1-derived turbulent jet ignition, Miller cycle, and variable geometry turbo to produce 324 hp at 40.5% thermal efficiency from just 2 liters.

Key Points

• 1.The Hurricane 4 uses a passive pre-chamber with turbulent jet ignition borrowed from Formula 1. The pre-chamber has 8 radial holes (~1mm) and 1 central hole (~0.5mm); ignited fuel shoots turbulent jets into the main chamber for faster, more complete combustion that resists knock and improves efficiency.
• 2.Specs are remarkable for a mainstream 2L four-cylinder. The engine produces 324 hp and 332 lb-ft of torque, runs a 12:1 compression ratio (high for a turbo engine), and hits up to 35 PSI of boost via a variable geometry turbocharger.
• 3.The engine runs the Miller cycle at all times by closing the intake valve early. This increases the expansion-to-compression ratio and reduces pumping losses by forcing the throttle to open wider at partial load, contributing directly to the engine's exceptional fuel efficiency.
• 4.Thermal efficiency reaches approximately 40.5% at 100 kW output, traced from Jeep's BSFC plot. This places the Hurricane 4 at the very bottom (most efficient) of the brake specific fuel consumption range versus all comparable mainstream four-cylinders, using 10% less fuel while making 20% more power than Jeep's current 2L turbo.
• 5.Dual spark plugs and dual fuel injectors are used with context-specific firing strategies. At low loads, the main chamber plug leads; at high loads, only the pre-chamber plug fires to avoid damaging the main plug in extreme heat and pressure. Port injection runs at idle for quiet operation; direct injection takes over at high loads for knock control.
• 6.The variable geometry turbo eliminates the need for a wastegate at high loads, a first in mainstream production. The wastegate is used solely to heat the catalytic converter on cold starts by bypassing the turbo entirely; at high loads, opening the vanes fully naturally limits boost, making the 35 PSI peak a rare high-altitude compensatory ceiling, not a constant operating pressure.