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If you drive a Mitsubishi Eclipse and want to protect its transmission under towing, spirited driving, or heavy traffic, the right transmission cooler can make a measurable difference. Choosing the correct unit helps manage fluid temperature, reduce wear, and maintain consistent shift performance over time. This guide highlights seven shortlisted transmission coolers selected as top options for the Mitsubishi Eclipse. We evaluated each choice for cooling effectiveness, build quality, and installation considerations to help you pick the right fit for your driving needs.
Looking for other parts? See all Mitsubishi Eclipse parts & accessories.
Top Picks at a Glance
| Best Reviewed A top-rated pick with lots of positive feedback | DriveMedley Transmission Oil Cooler, 8-Pass Tube-and-Fin |  |
| Most Popular A crowd favorite that many people choose with confidence | EVIL ENERGY 5/16" Transmission Oil Cooler Kit, 6-Pass Tube-and-Fin |  |
| Best Quality Built to a higher standard if you want something more solid | Ucreative 30-Row Stacked Plate Aluminum Transmission Oil Cooler Kit |  |
| Best Budget The cheapest option that still gets the job done reliably | FILTERUP 8-Pass Aluminum Transmission Oil Cooler Kit (5/16" Lines) |  |
| Most Sold A high-volume bestseller chosen again and again | KOROP LPD47391 40K Low Pressure Drop Transmission Oil Cooler Kit |  |
| Best Value for Money The sweet spot between price and what you get | Hayden Automotive Rapid-Cool Transmission Cooler Kit (Model 676) |  |
| Best Overall The best all-around choice for most situations | Gagsu LPD47391 Low Pressure Drop Transmission Oil Cooler (40,000 GVW) with Mounting Hardware |  |
1. DriveMedley Transmission Oil Cooler, 8-Pass Tube-and-Fin
| Core type | 8 Pass Tube and Fin |
|---|---|
| Hose ID compatibility | 5/16" ID lines |
| Material | Aluminum |
| Operating temperature range | -40°F to 257°F |
This DriveMedley transmission oil cooler is a compact aluminum, tube-and-fin cooler intended to lower transmission fluid temperature by routing fluid through eight internal passes while air flows over the fins. It is typically installed in front of the radiator or condenser and connects to 5/16" ID transmission lines using the supplied fittings and brackets. The cooler’s aluminum construction and multi-pass design improve heat transfer compared with single-pass coolers, which helps protect the transmission during towing, spirited driving, or extended highway runs. Included CPE hoses are rated for wide temperature ranges and high pressure, so they should hold up under normal operating conditions. Expect a straightforward bolt-on installation if you have clearance in the front bumper area, though you may need to adapt mounting hardware or use zip ties in tight spaces. This model is a universal-style cooler so you should verify fit and line routing for the Mitsubishi Eclipse before buying.
Best for: Reliability-focused buyers who prioritize protecting transmission life during heavier use on a Mitsubishi Eclipse and want an affordable aftermarket cooling upgrade.
Less Ideal for: Drivers who want a direct-fit, vehicle-specific cooler with factory-style mounting and instructions should consider a model made specifically for the Eclipse to avoid fabrication work.
- 8-pass tube-and-fin core for improved heat extraction compared with simpler coolers
- Aluminum construction offers good corrosion resistance and light weight for easier mounting
- Includes CPE hoses rated for a wide temperature range and high operational pressure
- Compact profile fits behind grille areas when space allows and includes mounting brackets
- Universal design requires measuring and possible modification for a precise fit on specific vehicles
- No vehicle-specific instructions included which can complicate installation for first-time installers
Verdict A compact, well-made universal 8-pass aluminum cooler that offers reliable extra transmission cooling for an Eclipse but may need fitment adjustments for a perfect install.
2. EVIL ENERGY 5/16" Transmission Oil Cooler Kit, 6-Pass Tube-and-Fin
| Compatibility | For lines with 5/16" ID |
|---|---|
| Core type | 6-pass tube-and-fin |
| Hose material | CPE |
| Working pressure | 145 PSI |
| Bursting pressure | 900 PSI |
This EVIL ENERGY kit provides a compact, tube-and-fin transmission cooler plus hose and basic fittings for adding auxiliary cooling to a Mitsubishi Eclipse that uses 5/16" ID transmission lines. It mounts where there is good airflow, typically ahead of the radiator or condenser, and the included CPE hose and clamps let you route fluid between the transmission and cooler without modifying the transmission itself. The 6-pass aluminum core helps shed heat effectively in stop-and-go driving and spirited runs, and reviewers report measurable temperature drops after installation. Because the kit is universal, expect to adapt or reflare factory lines or fabricate mounting brackets on the Eclipse; some customers found the supplied adapter fittings and clamps are basic and may not seal perfectly without a slight modification or better clamps. Installation instructions are included, and the cooler’s small footprint makes placement behind the grille straightforward, but sizing means it is better as an auxiliary cooler rather than a full replacement for larger factory-integrated systems.
Best for: Convenience-driven buyers who want a straightforward, budget-friendly way to lower transmission temperatures on a Mitsubishi Eclipse without a complex custom build or long parts searches.
Less Ideal for: Owners planning high-horsepower upgrades or who want a direct factory-style replacement should consider larger, vehicle-specific coolers or professional custom solutions instead.
- 6-pass aluminum tube-and-fin core provides effective heat rejection for supplemental cooling.
- Kit includes hoses and fittings so you can install without sourcing extra parts in most cases.
- Compact footprint fits in tight locations behind the grille for good airflow.
- Materials and machined exterior give a durable, aftermarket-quality build.
- Universal adapters and basic clamps may require reworking or upgraded fittings for a leak-free seal.
- Smaller core size may be insufficient as the only cooler on heavily modified or high-power setups.
- Being a universal kit you may need to fabricate mounting brackets for a clean OEM-like installation.
Verdict A compact, value-oriented auxiliary cooler for Mitsubishi Eclipse owners seeking easier installation and tangible temperature reduction, but expect to upgrade fittings or mounts for a factory-quality fit.
3. Ucreative 30-Row Stacked Plate Aluminum Transmission Oil Cooler Kit
| Rows | 30 |
|---|---|
| Oil capacity | 0.74L |
| Test pressure | 116 PSI |
| Burst pressure | 232 PSI |
This Ucreative 30-row stacked-plate transmission oil cooler is a compact, performance-focused solution for reducing transmission oil temps on a Mitsubishi Eclipse. It installs in front of the car where airflow is best and connects using the supplied AN adapters to braided lines, giving a leak-resistant, high-pressure path for transmission fluid. The stacked-plate design increases heat transfer area so you see faster temperature drops compared with single-pass coolers, and the aluminum construction resists corrosion while remaining lightweight. The kit includes 10AN-to-8AN and 10AN-to-6AN fittings and holds about 0.74 liters of oil, which helps lower operating temps during spirited driving or towing. Expect easy mounting in tight spaces, though you may need to fabricate or source brackets and routing hardware for a clean fit in the Eclipse’s front end. Installation instructions are not included, and long-term durability depends on careful line routing and torque on AN fittings, so professional installation is worth considering for high-stress builds.
Best for: Performance-oriented Mitsubishi Eclipse owners who prioritize lower transmission temperatures during spirited driving and are comfortable modifying mounting or plumbing for a custom install.
Less Ideal for: Drivers seeking a plug-and-play, factory-fit replacement or those unwilling to fabricate brackets or route braided lines should consider vehicle-specific kits or professional installation alternatives.
- High cooling capacity from 30 stacked plate rows for quicker oil temperature reduction
- Aluminum construction offers good corrosion resistance and light weight
- Includes common AN adapters (10AN to 8AN and 10AN to 6AN) for braided-line setups
- Compact footprint fits into tight front-end locations on performance cars
- No mounting brackets or installation instructions included
- May require additional fittings or custom brackets for neat fitment in the Eclipse
- Limited oil capacity compared with larger or twin-cooler setups if extreme cooling is needed
Verdict A compact, high-efficiency stacked-plate cooler that lowers transmission oil temperatures for performance-focused Mitsubishi Eclipse builds but needs extra mounting work for a finished install.
4. FILTERUP 8-Pass Aluminum Transmission Oil Cooler Kit (5/16" Lines)
| Core type | 8 pass tube-and-fin |
|---|---|
| Hose inner diameter | 5/16" |
| Core material | T-6061 aluminum |
| Hose material | CPE |
This FILTERUP 8-pass transmission oil cooler is a simple add-on kit that lowers transmission fluid temperature by increasing heat rejection through its tube-and-fin core. It installs inline with 5/16" ID transmission cooler lines and includes hoses, clamps, mounting rods and clips so you can mount it near the radiator or behind the bumper. The T-6061 aluminum core resists corrosion and the included CPE hose is flexible for tight routing. For a budget-focused upgrade it delivers clear benefits: cooler fluid under towing or spirited driving and potentially longer transmission life. Expect basic mounting hardware and thin external fins that can be bent or cut if handled roughly, so some buyers fabricate stronger brackets for a robust install. This unit is not a vehicle-specific direct-fit for the Mitsubishi Eclipse so plan for minor trimming and custom mounting to suit the Eclipse chassis and bumper openings.
Best for: Budget-conscious Mitsubishi Eclipse owners who want an affordable aftermarket transmission cooler to lower fluid temperatures for daily driving, light towing, or occasional spirited runs.
Less Ideal for: Owners seeking a plug-and-play, vehicle-specific cooler or those who require heavy-duty towing capacity and factory-quality mounting solutions should consider purpose-built, model-specific units instead.
- 8-pass T-6061 aluminum core for improved heat dissipation compared with single-pass coolers
- Includes hoses, clamps and mounting clips so you get a mostly complete install kit
- Flexible CPE hose simplifies routing in tight engine bays
- Lightweight, corrosion-resistant construction suitable for long-term use
- Not a vehicle-specific direct-fit so requires trimming and custom mounting for the Mitsubishi Eclipse
- Thin external fins are easy to bend or cut and mounting hardware is basic
- No internal baffling or manufacturer-specified flow rate provided
Verdict A cost-effective, lightweight 8-pass cooler that lowers transmission temperatures for Mitsubishi Eclipse owners willing to do minor custom fitment and mounting work.
5. KOROP LPD47391 40K Low Pressure Drop Transmission Oil Cooler Kit
| Connector Type | Flare |
|---|---|
| Thread Size | 3/8 |
| Thread Type | NPT |
| Material | Alloy Steel, Aluminum |
The KOROP LPD47391 is a brazed-aluminum transmission cooler kit that uses low-pressure-drop technology to increase heat transfer and keep transmission fluid cooler during towing or spirited driving. It installs as an auxiliary inline cooler and ships with brackets, bolts, and fittings to simplify mounting. In real-world use it drops operating temps materially for many users, which can reduce wear and help prevent overheating under load. The kit supports a 40,000 GVW rating and uses 3/8-inch flare/NPT connections, so it pairs with compatible line fittings or adapters when needed. Reported issues include occasional hose quality problems and nonstandard fittings that may require sourcing adapters or replacement hoses for a clean install. Expect to drill new mounting holes in some applications rather than using factory locations. The kit is straightforward for a competent DIYer and offers a cost-effective way to add extra transmission cooling to a vehicle like the Mitsubishi Eclipse when matching fittings and space allow.
Best for: Risk-averse mainstream buyers who prioritize protecting the transmission from overheating and want an affordable, factory-style auxiliary cooler they can install or have installed with minimal fuss.
Less Ideal for: Buyers seeking a plug-and-play, vehicle-specific cooler for unusual or extremely tight under-hood layouts should consider a model engineered specifically for the Eclipse or professional installation with custom lines.
- Brazed-aluminum core with low-pressure-drop design for efficient heat transfer
- Complete mounting hardware included to simplify installation
- Rated for heavy-duty 40,000 GVW applications, suitable for towing or higher-load use
- Multiple fittings and adapters in the kit help with fitment variations
- Supplied rubber hose quality has produced failures for some users
- Uses 3/8 inverted flare/NPT fittings that may not match factory lines and can require adapters or custom hoses
- May require drilling new mounting holes as it does not always fit factory bracket locations
Verdict A budget-friendly, brazed-aluminum 40K cooler kit that effectively lowers transmission temperatures but may need hoses or adapters for a flawless fit on some vehicles.
6. Hayden Automotive Rapid-Cool Transmission Cooler Kit (Model 676)
| Core type | Plate-and-fin |
|---|---|
| Fittings | 19 mm barb fittings |
| Mounting | Pre-drilled vehicle mount brackets |
| Material | Steel |
The Hayden Rapid-Cool Model 676 is a compact add-on transmission cooler kit that installs in series with the factory cooling lines to lower transmission fluid temperature. It uses a plate-and-fin core with patented internal turbulation to boost heat transfer while keeping pressure drop low. The kit includes the cooler, a length of hose, pre-drilled mounting brackets and basic hardware for a simple vehicle-mount installation. In practice this cooler is useful for street-driven Mitsubishi Eclipse models that see spirited driving or occasional towing because it helps keep fluid cooler and shifting more consistent. Installation is straightforward for a competent DIYer but you may need extra hose or fittings depending on routing in the Eclipse’s front end. The cooler is not a direct factory replacement so it requires finding a suitable mounting location and fitting to the Eclipse’s transmission lines. Expect solid temperature control and durable construction, but plan for minor fabrication or additional parts on some installations.
Best for: Practical optimizers who want an affordable, proven add-on to reduce transmission operating temperature and extend service life on a Mitsubishi Eclipse through targeted cooling upgrades.
Less Ideal for: Drivers seeking a bolt-in, vehicle-specific direct replacement or a cooling solution for heavy-duty towing should consider purpose-built fitment kits instead.
- Plate-and-fin core with patented internal turbulation for improved heat transfer
- Pre-drilled mounting brackets simplify attachment to a vehicle mount
- Includes hose and basic hardware for a quicker DIY install
- Compact footprint fits behind the grille or in tight front-end locations
- Not a direct factory replacement so custom mounting and line adapters are required
- Supplied hose length may be short for some routing needs requiring additional hose
- No vehicle-specific instructions for Mitsubishi Eclipse included
Verdict A compact, well-made add-on cooler that gives Mitsubishi Eclipse owners good cooling performance for the money but requires basic customization for fitment.
7. Gagsu LPD47391 Low Pressure Drop Transmission Oil Cooler (40,000 GVW) with Mounting Hardware
| Model | LPD47391 |
|---|---|
| Manufacturer | Gagsu |
| Max GVW | 40,000 pounds |
| Exterior | Metal |
The Gagsu LPD47391 is an external transmission oil cooler intended to lower operating temperatures for heavy-duty use and towing. It installs ahead of the transmission lines using the supplied brackets, bolts, and fittings, and its low-pressure-drop design helps maintain line pressure while improving heat rejection. In real-world use it is fitted inline to route hot transmission fluid through the finned cooler where airflow dissipates heat; owners report substantial temperature drops on highway and towing duty. The kit includes mounting hardware to simplify installation, but several users noted bent fins from handling, basic hose clamps, and occasional debris or casting flash in the ports that should be flushed before use. While the cooler can noticeably reduce transmission temps on an Eclipse that is used for spirited driving or regular towing, careful pre-install inspection, replacing the supplied clamps, and using quality transmission hose will reduce installation issues. There are reports of rare casting failures, so this is best for drivers who will inspect the unit and perform a careful install rather than expecting a maintenance-free lifetime product.
Best for: Balanced all-round buyers who want a practical, effective transmission cooling upgrade for a Mitsubishi Eclipse used for spirited driving or occasional towing and who prioritize measurable temperature reduction over premium factory-quality fit and finish.
Less Ideal for: Drivers seeking a plug-and-play, fully guaranteed lifetime component without any pre-install inspection or those unwilling to replace basic supplied hardware should consider a higher-end, fully tested factory-quality cooler instead.
- Low-pressure-drop core reduces pressure loss while improving cooling effectiveness.
- Comes with mounting hardware for a simpler bolt-on installation.
- Proven to significantly lower transmission temperatures under load in user reports.
- Metal exterior and finned design provide effective heat dissipation.
- Suitable for heavy-duty cooling needs up to 40,000 GVW applications.
- Some units arrive with aluminum shavings or casting flash in the ports that require cleaning before installation.
- Included hose clamps and small fasteners are basic and many users replace them with higher-quality parts.
- Fins are fairly easy to bend during handling which can reduce airflow and cooling if not straightened carefully.
Verdict A cost-effective, low-pressure-drop cooler that reliably cuts transmission temps for a Mitsubishi Eclipse when installed and inspected carefully, but expect to upgrade clamps and check ports before use.
Choosing the Right Mitsubishi Eclipse Transmission Cooler: Key Factors to Consider
Cooling Capacity And Core Size
Cooling capacity determines how effectively the unit lowers transmission fluid temperature under load. A larger core or greater surface area typically sheds more heat, which matters during prolonged high-load driving, towing, or stop-and-go traffic.
However, bigger is not always better if it obstructs airflow or complicates fitment. Consider the available mounting space on the Eclipse and aim for a cooler that provides measurable temperature drop without interfering with other components.
Material And Build Quality
Materials affect longevity and resistance to road corrosion. Aluminum cores and brass or aluminum fittings are common because they balance weight, heat transfer, and corrosion resistance. Look for robust welds or brazing on connections and durable end tanks to reduce leak risk.
Quality construction also mitigates vibration-related fatigue. A well-built cooler will tolerate engine bay conditions without cracking or developing slow leaks over time.
Mounting And Fitment
Mounting options determine how easily you can secure the cooler to the vehicle. Brackets that attach to existing chassis points or the radiator support simplify installation and reduce the need for custom fabrication. Consider whether there is room in front of the radiator, behind the bumper, or along the frame rail on the Mitsubishi Eclipse for the chosen cooler.
A model with multiple mounting points or adjustable brackets can be useful in tight spaces and helps ensure adequate airflow through the core.
Hose Compatibility And Connections
Pay attention to inlet and outlet fittings and whether the cooler uses barbed, threaded, or quick-disconnect connections. Matching hose diameter and fitting type to the Eclipses transmission lines reduces the need for adapters and potential leak points.
Also consider the routing length and whether additional transmission cooler lines or adapters will be required to maintain proper fluid flow without undue bends or kinks.
Pressure Drop And Flow Characteristics
A cooler should provide heat reduction with minimal restriction to fluid flow. Excessive pressure drop can impede transmission lubrication and cooling, particularly in systems with mechanical pumps designed for specific flow rates.
Look for coolers that list flow rates or are designed to be added in parallel with factory cooling to preserve circulation while increasing thermal capacity.
Ease Of Installation And Maintenance
Ease of installation affects total ownership cost and reliability. Kits that include necessary mounting hardware, fittings, and clear instructions reduce installation time and potential mistakes. Consider whether the installation requires bleeding the system or draining fluid, and whether you can perform routine inspections for leaks or blockages without major disassembly.
Maintenance-friendly designs have accessible fittings and do not place the cooler where road debris or damage is likely.
FAQ
Do I need a transmission cooler for my Mitsubishi Eclipse?
You may benefit from an additional cooler if you frequently tow, drive in heavy traffic, or push the car hard. Extra cooling helps control fluid temperature and can reduce wear under sustained load, though everyday commuting may not always require one.
Can I install a transmission cooler myself on an Eclipse?
Many owners can install an external cooler with basic hand tools, but complexity depends on mounting location and hose routing. Kits that include fittings and brackets simplify the job. If you are uncomfortable routing lines or bleeding fluid, professional installation is a sensible option.
Where is the best place to mount an external transmission cooler on the Eclipse?
Common mounting spots are in front of the radiator or condenser to maximize airflow and cooling. Alternatively, mounting along a frame rail can work if airflow is adequate. Pick locations that avoid sharp edges, moving parts, and high-heat surfaces, and that allow secure bracket attachment.
Will adding a cooler change transmission fluid maintenance intervals?
An effective cooler can reduce operating temperatures and may decrease thermal stress on the fluid, which can help prolong its useful life. However, follow the manufacturers service recommendations for fluid checks and changes, since other factors also affect fluid condition.
How do I know if my transmission cooler or lines are failing?
Common signs include fluid leaks around fittings or lines, rising transmission temperatures under similar driving conditions, or a noticeable drop in shift quality. Inspect fittings and hoses for cracks, swelling, or corrosion, and address any leaks promptly to avoid fluid loss.
How We Chose the Best Mitsubishi Eclipse Transmission Cooler
Selections focused on real-world durability and thermal performance relevant to the Mitsubishi Eclipse. We prioritized coolers with proven heat-exchange efficiency, materials that resist corrosion and vibration, and construction suitable for the vehicles typical engine bay constraints. Mounting options and hose compatibility were key, since the available space and factory plumbing on the Eclipse affect installation ease and reliability. We considered flow capacity and pressure tolerance to ensure the cooler would handle higher loads without restricting fluid circulation. Long-term maintenance factors such as line accessibility and serviceability influenced decisions. Units that required significant modification, offered incompatible fittings, or lacked sufficient thermal data were excluded. The final list emphasizes practical balance between cooling capacity, durability, and straightforward installation for the Mitsubishi Eclipse.
Our full evaluation process is outlined in our review methodology.
Conclusion
Choosing the right transmission cooler for a Mitsubishi Eclipse is a matter of balancing cooling capacity, fitment, and ease of installation. Prioritize a unit that reliably lowers fluid temperature without restricting flow and that fits into the available mounting space without complex modification. Consider material quality and hose compatibility to reduce leak risk and maintenance time. If you tow or drive under high load frequently, favor cooling performance and robust mounting. For lighter use, focus on compact fitment and straightforward installation.
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