CSF 3966 Radiator
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CSF

CSF 3966 Radiator

Brand CSF 3966
Core Thickness 5/8
Core Width 17
Core Material Aluminum
Tank Material Plastic
Core Length 26 9/16
Inlet Diameter 1 5/16 right
Outlet Diameter 1 5/16 left
Down Flow Or Cross Flow Type Cross flow
Box Height (in) 5 7/8
Box Length (in) 34 3/16
Box Weight (lbs) 8
Box Width (in) 21 3/16
Hazardous Material No
Inlet Length (in) 17 7/16
Inlet Width (in) 1 3/8
No. Of Rows 1
Oil Cooler (in) No
Outlet Length (in) 17 7/16
Outlet Width (in) 1 3/8
Radiator Cap Supplied No
Tech Note O.e.m. style plastic tank & aluminum core. upgraded heavy duty co
Fits Mazda · 7 vehicles

Heavy-duty upgrade. 42% thicker core than OEM for stronger cooling performance.

OE-style construction. Plastic tanks and aluminum core match the original design.

Proven engineering. Wind-tunnel tested and built to validated cooling standards.

Cross-references PAF3-15-200A and PAF3-15-200B for the same application. See all 2.

$149.00Free shipping
In stock · usually ships same day before 1pm CST
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Step 2 — Quantity
Order total $149.00
Free shipping to the continental U.S.
Free returns within 60 days if it doesn't fit when fitment is verified.
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CSF 3966 Radiator for Mazda 3 and CX-30

CSF 3966 is an OE-style radiator built with a plastic tank and aluminum core for select Mazda applications. It is engineered as an upgraded heavy-duty replacement with a thicker core than the original design, making it a direct-fit option for 2019-2022 Mazda 3 and 2020-2022 Mazda CX-30 models.

Key Features

  • OE-style radiator construction with plastic tanks and aluminum core
  • Cross flow design with one-row core
  • Core thickness: 5/8 in.
  • Core dimensions: 17 in. wide x 26 9/16 in. long
  • Inlet diameter: 1 5/16 in., right side
  • Outlet diameter: 1 5/16 in., left side
  • Upgraded heavy-duty core, 42% thicker than OEM 11 mm design
  • CSF part number 3966

Detailed Description

CSF 3966 radiator is designed for drivers who need a direct replacement for the factory cooling unit in select Mazda 3 and Mazda CX-30 models. The aluminum core and plastic tank layout follows OE-style construction, while the upgraded core thickness adds capacity over the original 11 mm design. CSF manufactures radiators to high-performance standards and validates cooling performance through laboratory wind tunnel testing. This part cross-references PAF3-15-200A and PAF3-15-200B for the same application.

What This Radiator Helps Address

  • Overheating caused by a worn or restricted radiator core
  • Coolant leaks from aging plastic tank and core assemblies
  • Reduced cooling efficiency in stop-and-go driving
  • Heat buildup from a damaged or corroded factory radiator
  • Replacement needs for a failed Mazda 3 radiator or Mazda CX-30 radiator

Installation Notes and Tips

Fits 2019-2022 Mazda 3, N/A. Fits 2020-2022 Mazda CX-30, N/A. Verify inlet and outlet orientation before installation: inlet is on the right and outlet is on the left. Confirm all hose connections, mounting points, and cooling system components match the original radiator before installation. CSF 3966 uses a cross flow layout and does not include a radiator cap.

Quality Assurance

CSF radiators are manufactured in ISO/TSO-certified facilities and built for global OE and aftermarket use. The brand reports more than 30 million radiators sold worldwide and uses laboratory testing to validate cooling performance.

Related reading

This part fits 7 vehicles
Always verify fitment with your vehicle's VIN if unsure. Submodel & trim restrictions may apply.
YearMakeModelBody TypeLitersCylindersPositionNotes
2022Mazda3Sedan2.0LL4N/AUpgraded Heavy Duty Core. 42% Thicker 15.5mm vs OEM 11mm
2022MazdaCX-30—2.0LL4N/AUpgraded Heavy Duty Core. 42% Thicker 15.5mm vs OEM 11mm
2021Mazda3Sedan2.0LL4N/AUpgraded Heavy Duty Core. 42% Thicker 15.5mm vs OEM 11mm
2021MazdaCX-30—2.5LL4N/AUpgraded Heavy Duty Core. 42% Thicker 15.5mm vs OEM 11mm
2020Mazda3Sedan2.5LL4N/AUpgraded Heavy Duty Core. 42% Thicker 15.5mm vs OEM 11mm
2020MazdaCX-30—2.5LL4N/AUpgraded Heavy Duty Core. 42% Thicker 15.5mm vs OEM 11mm
2019Mazda3Sedan2.0LL4N/AUpgraded Heavy Duty Core. 42% Thicker 15.5mm vs OEM 11mm
Directly replaces or cross-references 2 part numbers
Cross-reference numbers are provided for identification purposes only. Always confirm fitment before ordering.
PAF3-15-200APAF3-15-200B