CSF Audi B5 A4 1.8T High-Performance Radiator

The Audi/VW 1.8L 20v turbo inline-4 is a genuinely great motor, proven stout when making more power while keeping the B5 A4's weight low enough to stay fairly light and nimble. A few bolt-ons, new turbos, and a tune can quickly get you to double the original horsepower of the motor, but those power gains come at the cost of a lot of extra heat. CSF developed this High-Performance All-Aluminum Radiator specifically for enthusiasts making more power and pushing their Audi to the limit, whether that's autocross, drag racing, track driving, or simply hitting the backroads with vigour.

The 2-row, 42mm core uses a dual-pass configuration built around CSF's exclusive B-Tube technology. Rather than a regular oval "O"-shaped tube, a specially engineered "B"-shaped tube is carefully formed and brazed over the seam, increasing heat transfer surface area by approximately 15% over regular tubes while allowing for thinner, lighter aluminium construction that's genuinely stronger than a normal welded design, delivering true dual liquid laminar flow. The larger core doesn't just improve heat dissipation, it also increases fluid capacity significantly over the factory unit, and more cooling tubes mean more surface area for the coolant's heat to dissipate from. Super-efficient multi-louvered fins maximise airflow through the core, and 100% all-aluminium, TIG-welded construction increases overall strength considerably over the factory design. CNC-machined, welded OE-style brackets ensure a genuine drop-in fit requiring no modifications to install.

Works with: OEM mounting points and hose connections. True drop-in fit.

Why Choose This Radiator

• Dual-pass, 2-row, 42mm core with CSF's exclusive B-Tube technology
• Approximately 15% more heat transfer surface area than regular tubes, genuine dual liquid laminar flow
• Significantly increased fluid capacity over the OEM unit
• 100% all-aluminium, TIG-welded construction for genuine long-term strength
• CNC-machined, welded OE-style brackets for a precise, durable fit
• True drop-in fit, no modifications required

Compatibility

• Audi A4 (B5, 1996-2001, 1.8T)