USE COUPON CODE "SUMMER26"

Your cart

Your cart is empty

Shop 4.0L

Upgrade Your 4.0L Engine with FastHemis The 4.0L inline-six engine is known for its durability and smooth power delivery, commonly found in Jeep models like the Wrangler and Cherokee. Its robust design offers a solid foundation for both daily driving reliability and moderate performance enhancements. At FastHemis, you'll find a range of parts tailored to the 4.0L platform, including intake and exhaust upgrades, ignition components, and tuning accessories. These parts help improve throttle response, efficiency, and overall engine capability without compromising the engine’s legendary reliability. Key upgrades for your 4.0L engine include: - High-flow air intake systems - Performance exhaust components - Ignition and spark upgrades - Engine management and tuning tools Shop 4.0L engine upgrades at FastHemis.
SELECT YOUR VEHICLE

1006 Results

Spec D Crystal Headlights (Smoke): Jeep 1999 - 2004

Spec D

Regular price $105.00 $78.00 26% off

Unit price
per 

Spec D Crystal Headlights (Chrome): Jeep Grand Cherokee 1999 - 2004
Spec D Crystal Headlights (Chrome): Jeep Grand Cherokee 1999 - 2004

Spec D Crystal Headlights (Chrome): Jeep Grand Cherokee 1999 - 2004

Spec D

Regular price $97.00 $72.00 26% off

Unit price
per 

Spec D Projector Halo Headlights (Glossy Black): Jeep Grand Cherokee 1999 - 2004
Spec D Projector Halo Headlights (Glossy Black): Jeep Grand Cherokee 1999 - 2004

Spec D Projector Halo Headlights (Glossy Black): Jeep Grand Cherokee 1999 - 2004

Spec D

Regular price $198.00 $147.00 26% off

Unit price
per 

Spec D Crystal Headlights (Smoke, Version 2): Jeep 1999 - 2004

Spec D

Regular price $100.00 $74.00 26% off

Unit price
per 

DFC D&S Rotor (FRONT LEFT): Jeep Wrangler (99-06)
DFC D&S Rotor (FRONT LEFT): Jeep Wrangler (99-06)

DFC D&S Rotor (FRONT LEFT): Jeep Wrangler (99-06)

DFC

$140.60

Unit price
per 

Stopping Power
Noise Level
Performance Over Stock
Dust Levels
Liqui Moly Speed Tec Gasoline: Fits Most Models
Liqui Moly Speed Tec Gasoline: Fits Most Models

Liqui Moly Speed Tec Gasoline: Fits Most Models

LIQUI MOLY

$101.70

Unit price
per 

Kentrol Powder Coated Footman Loop: 97-18 Jeep Wrangler TJ / JK
usa

Kentrol Powder Coated Footman Loop: 97-18 Jeep Wrangler TJ / JK

Kentrol

Regular price $24.13 $22.76 6% off

Unit price
per 

Kentrol Polished Silver Windshield Wiper Arms Pair: Jeep Wrangler TJ 1997-2006
usa

Kentrol Polished Silver Windshield Wiper Arms Pair: Jeep Wrangler TJ 1997-2006

Kentrol

Regular price $97.63 $92.06 6% off

Unit price
per 

R1 Concepts Drilled & Slotted Brake Rotor (REAR RIGHT): Jeep Grand Cherokee 1999-2004 2.5L/4.0L

R1 Concepts Drilled & Slotted Brake Rotor (REAR RIGHT): Jeep Grand Cherokee 1999-2004 2.5L/4.0L

R1 Concepts

$98.80

Unit price
per 

Stopping Power
Noise Level
Performance Over Stock
Dust Levels
R1 Concepts Drilled & Slotted Brake Rotor (REAR LEFT): Jeep Grand Cherokee 1999-2004 2.5L / 4.0L

R1 Concepts Drilled & Slotted Brake Rotor (REAR LEFT): Jeep Grand Cherokee 1999-2004 2.5L / 4.0L

R1 Concepts

$98.80

Unit price
per 

Stopping Power
Noise Level
Performance Over Stock
Dust Levels
R1 Concepts Drilled & Slotted Brake Rotor (FRONT RIGHT): Jeep Grand Cherokee 1999-2004 2.5L / 4.0L

R1 Concepts Drilled & Slotted Brake Rotor (FRONT RIGHT): Jeep Grand Cherokee 1999-2004 2.5L / 4.0L

R1 Concepts

$114.80

Unit price
per 

Stopping Power
Noise Level
Performance Over Stock
Dust Levels
R1 Concepts Drilled & Slotted Brake Rotor (FRONT LEFT): Jeep Grand Cherokee 1999-2004 2.5L/4.0L

R1 Concepts Drilled & Slotted Brake Rotor (FRONT LEFT): Jeep Grand Cherokee 1999-2004 2.5L/4.0L

R1 Concepts

$114.80

Unit price
per 

Stopping Power
Noise Level
Performance Over Stock
Dust Levels
Artec Industries Bushings for UCA Mount: Jeep Wrangler (97-06)
usa

Artec Industries Bushings for UCA Mount: Jeep Wrangler (97-06)

Artec Industries

$54.99

Unit price
per 

Energy Suspension 1in Body Lift Kit: Jeep Wrangler 1994-2006
Energy Suspension 1in Body Lift Kit: Jeep Wrangler 1994-2006
usa

Energy Suspension 1in Body Lift Kit: Jeep Wrangler 1994-2006

Energy Suspension

Regular price $425.58 $283.72 33% off

Unit price
per 

Edge EvoHT2 Handheld Tuner: Fits Most GM / Ford / Dodge RAM Trucks

Edge EvoHT2 Handheld Tuner: Fits Most GM / Ford / Dodge RAM Trucks

Edge

Regular price $518.95 $349.95 33% off

Unit price
per 

DFC 4000 HybriDynamic Front Brake Pads w/ Hardware: Jeep Grand Cherokee (99-04)

DFC 4000 HybriDynamic Front Brake Pads w/ Hardware: Jeep Grand Cherokee (99-04)

DFC

$56.00

Unit price
per 

Stopping Power
Performance Over Stock
Dust Levels
Rancho RS5000X Rear Shock: Jeep Wrangler 1997-2006 (RS55240)
Rancho RS5000X Rear Shock: Jeep Wrangler 1997-2006 (RS55240)
Rancho RS5000X Rear Shock: Jeep Wrangler 1997-2006 (RS55241)
Rancho RS5000X Rear Shock: Jeep Wrangler 1997-2006 (RS55241)
Magnaflow Universal Catalytic Converter: Jeep Wrangler 1997 - 1998
Magnaflow Universal Catalytic Converter: Jeep Wrangler 1997 - 1998
usa
Method Wheels 707 / Matte Black | 17x8.5 | 5x5 | 0/4.72"
Method Wheels 707 / Matte Black | 17x8.5 | 5x5 | 0/4.72"

Method Wheels 707 / Matte Black | 17x8.5 | 5x5 | 0/4.72"

Method Wheels

$366.00

Unit price
per 

Billetworkz Shift Knob Hoodie SRT
usa

Billetworkz Shift Knob Hoodie SRT

Billetworkz

$25.00

Unit price
per 

Billetworkz Shift Knob Hoodie: Fits Universal up to 2in Diameter
usa
Billetworkz Shift Knob Hoodie Jeep Grill
usa

Billetworkz Shift Knob Hoodie Jeep Grill

Billetworkz

$25.00

Unit price
per 

Billetworkz Shift Knob Hoodie Hellcat
usa

Billetworkz Shift Knob Hoodie Hellcat

Billetworkz

$25.00

Unit price
per 

Billetworkz Shift Knob Hoodie R/T: Fits Universal up to 2in Diameter
usa
Artec Industries Front Axle Swap Kit: Jeep Wrangler w/ Standard Hole
usa
Artec Industries 8.8 Swap Kit: Jeep Wrangler (93-06)
usa

Artec Industries 8.8 Swap Kit: Jeep Wrangler (93-06)

Artec Industries

$45.09

Unit price
per 

DFC GeoSPEC Coated Brake Rotor (FRONT): Jeep Wrangler 2.0L / 2.5L (99-06)
DFC GeoSPEC Coated Brake Rotor (FRONT): Jeep Wrangler 2.0L / 2.5L (99-06)

DFC GeoSPEC Coated Brake Rotor (FRONT): Jeep Wrangler 2.0L / 2.5L (99-06)

DFC

$71.50

Unit price
per 

Stopping Power
Noise Level
Performance Over Stock
Dust Levels

Performance Upgrades for Your 4.0L Inline-Six Engine

The 4.0L inline-six engine is a durable and smooth-running powerplant widely recognized in Jeep Wrangler and Cherokee models. Known for its reliability and balanced power delivery, this engine offers a solid base for bolt-on performance enhancements that improve throttle response and efficiency without sacrificing longevity.

Key Performance Upgrades for the 4.0L Engine

Enhancing your 4.0L engine focuses on improving airflow, ignition, and engine management to unlock better throttle response and overall drivability. Popular upgrades include high-flow intake systems that increase air volume, performance exhaust components that reduce backpressure, and ignition upgrades that ensure stronger, more consistent sparks.

  • High-flow air intake systems to boost airflow and efficiency
  • Performance exhaust components for improved scavenging and sound
  • Ignition and spark upgrades to optimize combustion
  • Engine management and tuning tools for precise calibration

How to Maintain Reliability While Upgrading Your 4.0L

The 4.0L engine’s reputation for durability means upgrades should complement its robust design without over-stressing components. Focus on bolt-on parts that enhance performance within the engine’s mechanical limits. Proper tuning and quality parts help maintain reliability while extracting more capability from your engine.

Find the Right 4.0L Engine Parts at FastHemis

At FastHemis, we offer a curated selection of 4.0L engine upgrades designed to improve performance and maintain reliability. Whether you’re looking for intake kits, exhaust solutions, ignition components, or tuning accessories, our parts are fitment-focused and engineered for your Jeep’s inline-six. Shop the 4.0L collection today to enhance your engine’s capability.

SELECT YOUR VEHICLE