Performance Koyo Radiator, Mazda 3, BK, 04/09, 25mm, (KS061816) (NEW)

Koyo Radiator KS061816 for 2004–2009 Mazda 3 BK SP23 — Hyper KH-Series 25mm Core

The Koyo Radiator KS061816 is a high-performance, direct-fit upgrade designed for 2004–2009 Mazda 3 BK SP23 (non-turbo) models. Featuring Koyo’s compact yet efficient 25mm Hyper KH-Series core, this radiator delivers superior cooling performance while saving space and reducing weight—ideal for Kiwi drivers who want more cooling power without any mods.

Manufactured in Koyorad’s world-renowned ISO-certified factories in Japan, this radiator features precise tube and fin alignment, Nocolok brazing, and hand-crafted heliarc welds for next-level strength and thermal performance. It bolts right into the factory mounting points, works with stock fan shrouds and hoses, and keeps your SP23 running sweet as under pressure.

Automatic transmission vehicles will require an external Davies Craig DC-677 cooler. Hyper Cap sold separately.

Features & Benefits

• Compact 25mm Hyper KH core offers top-tier cooling while saving space under the bonnet

• Nocolok brazed construction resists vibration, corrosion, and NZ’s rough backroads

• Billet filler neck ensures secure sealing and durability under high temps

• Direct OE fit—uses factory fan shrouds, mounts, and hoses for easy install

• Hand-crafted heliarc welds provide long-lasting strength and reliability

• Lightweight build increases coolant volume without unnecessary bulk

Made for Kiwi Drivers

From daily runs through Wellington’s hills to summer roadies up North, the Koyo KS061816 radiator keeps your Mazda 3 cool and cruising. Built to handle Aotearoa’s demanding conditions with ease and efficiency.

Technical Specifications

Vehicle Compatibility

What's Included

• 1 × Koyo Radiator KS061816 (25mm Hyper KH-Series core)

• 1 × Pre-installed drain plug

• OE-fit mounting for hoses and fan shrouds

• Installation-ready packaging

• Product and warranty documentation

REVIEWS

DJ
Fitted this into my SP23—perfect fit, temps dropped straight away and build quality is top-tier. Real happy with the upgrade.

Daniel J.
Tauranga, NZ
★★★★★

NC
Was overheating on the hills, chucked in the Koyo and haven’t had a drama since. Install was easy, and it’s solid as.

Nina C.
Invercargill, NZ
★★★★★