

Koyo (Koyorad) Performance Radiator: Lexus IS250 / IS350 GSE20 / GSE21 / GSE25 2005+
$799.00
or 4 interest-free payments of $199.75 with Afterpay
Part no. KH011937
Available to order - allow extra time for delivery
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Koyo Performance Radiator – Lexus IS250 / IS350 GSE20 / GSE21 / GSE25 2005+
Application: Lexus IS250 / IS350 | DBA-GSE20 / DBA-GSE21 / DBA-GSE25 | 4GR-FSE / 2GR-FSE | 2005+
The Lexus IS250 and IS350 represent the sharp end of Toyota's rear-wheel-drive performance sedan lineup — refined, capable machines that are increasingly popular as track and street performance builds. The 4GR-FSE and 2GR-FSE engines are smooth, high-revving units that benefit from improved thermal management, particularly under sustained high-load driving conditions.
Koyorad's all-aluminium KH011937 is a direct bolt-in performance upgrade engineered specifically for the GSE20-series IS platform. Nocolok furnace brazed, precision TIG welded by hand, and triple pressure tested — it retains all OEM fan shroud mounts and stock hose connections with no modifications required.
Why Koyorad?
- Precise Tube & Fin Alignment — Strict quality control ensures optimal coolant flow and maximum heat transfer efficiency across the entire core.
- Nocolok Furnace Brazing — All tubes, fins, headers, and brackets are bonded in a state-of-the-art Nocolok furnace, creating a structure that resists vibration, road debris, and the elements.
- Billet Filler Neck — Precision-machined billet filler necks are fitted to every unit for superior strength, durability, and a reliable seal.
- OE-Specific Mounting — Application-specific mounting points for fan shrouds, inlet/outlet hoses, and top/bottom pins ensure a pain-free, no-modification install.
- Hand-Crafted Heliarc Welds — Each radiator is individually Heliarc welded by hand, creating the strongest possible aluminium-to-aluminium bond across all components.
Specifications
- Part Number: KH011937
- Core Thickness: 48mm
- Core Dimensions (H × W): 375 × 704/728mm
- Tank Dimensions: 55/55 × 735mm
- Inlet / Outlet Diameter: TBA
- Construction: All Aluminium, Nocolok Brazed, Heliarc Welded
- Fan Shroud: Retains OEM mounts
- Hoses: Compatible with stock radiator hoses
- Fitment: Direct bolt-in, no modifications required
Cross Reference
- Koyorad: KH011937
- Lexus / Toyota OEM: 16400 31440
Fitment
- Year · Make · Model · Chassis · Submodel
- 2005+ · Lexus · IS250 · DBA-GSE20 · 4GR-FSE 2.5L
- 2005+ · Lexus · IS350 · DBA-GSE21 · 2GR-FSE 3.5L
- 2005+ · Lexus · IS250 · DBA-GSE25 · 4GR-FSE 2.5L
Sold individually. Lead times may apply — contact us for availability and shipping estimates.
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