CSF
CSF Audi B5 A4 1.8T High-Performance All-Aluminum Radiator
BACKORDER - AVAILABLE
Pay later options
Spread the cost of your order. Choose your provider at checkout — nothing to set up here.
KLARNA FINANCE
Part 1: How it works
Shop now. Pay later with Klarna.
Please spend responsibly. Borrowing more than you can afford could seriously affect your financial status. Make sure you can afford to make your monthly repayments on time.
Step 1: Add products to your cart and select “Klarna” when you check out
Step 2: Enter a few personal details and you’ll know instantly if you’re approved
Step 3: Klarna will send you an email confirmation and reminders when it’s time to pay and you can manage your orders and payments in the Klarna app.
Part 2: Payments information
Pay in 30 days
Make your purchase today so you can try before you buy. Only pay for what you keep. Pay up to 30 days later. No interest. No fees. No impact to your credit score.
Paying after delivery allows you to try before you buy and is the easiest way to shop online.
- Complete the payment in full after purchase at no added cost.
- Report returns directly in our app and only pay for the items that you keep.
- Not making your payment on time could affect your ability to use Klarna in the future.
- Debt collection agencies are used as a last resort
You must be 18+ and a UK resident to be eligible for this credit offer. Pay Later Terms and Conditions
Pay in 3 interest-free instalments
Spread the cost of your purchase into 3 interest-free instalments. The first payment is made at point of purchase, with remaining instalments scheduled automatically every 30 days. No interest or fees. Select the Klarna option and enter your debit or credit card information. To check your eligibility, Klarna will perform a soft search with a credit reference agency. This will not affect your credit score.
No interest. No fees. No impact to your credit score.
- A new way to pay that's an alternative to a credit card.
- 3 instalments gives you flexibility to shop without interest or hidden fees. - Not making your payment on time could affect your ability to use Klarna in the future.
- Debt collection agencies are used as a last resort.
You must be 18+ and a UK resident to be eligible for this credit offer. Pay in 3 Terms and Conditions
Part 3: About Klarna
Pay online or in the app
Review your latest purchases and make payments in the Klarna app or online.
● Download the Klarna app: https://www.klarna.com/app
● Log in online: https://app.klarna.com/login
● Chat with customer service: https://www.klarna.com/uk/customer-service/
Safe and secure
With Klarna, you are always covered through Klarna’s Buyer Protection policy. Modern safeguards protect your information to prevent unauthorized purchases.Frequently asked questions
Visit our FAQ (https://www.klarna.com/uk/customer-service/) page to find out more about using Klarna.About Klarna
At Klarna, we have a relentless focus on creating the best shopping experience in the world. We believe payments are so much more than just a way to send money. That’s why our smooth checkout options give you more time and control so you can focus on the things you love.● More than 90 million shoppers are using Klarna.
● 200,000 retailers are working with us worldwide.
● We’re one Europe’s largest banks and we’ve been powering online checkouts for over 15 years.
Please spend responsibly. Borrowing more than you can afford could seriously affect your financial status. Make sure you can afford to make your monthly repayments on time.
R44 Performance Ltd. is not a lender and acts only as an introducer. The credit product is provided by Klarna Bank AB (publ). Credit is only available to permanent UK residents aged 18 and over, depending on their status. Terms and conditions apply. Please note that Pay in 30 days and Pay in 3 instalments are not regulated by the FCA.
Choose options
BACKORDER - AVAILABLE
Pay later options
Spread the cost of your order. Choose your provider at checkout — nothing to set up here.
KLARNA FINANCE
Part 1: How it works
Shop now. Pay later with Klarna.
Please spend responsibly. Borrowing more than you can afford could seriously affect your financial status. Make sure you can afford to make your monthly repayments on time.
Step 1: Add products to your cart and select “Klarna” when you check out
Step 2: Enter a few personal details and you’ll know instantly if you’re approved
Step 3: Klarna will send you an email confirmation and reminders when it’s time to pay and you can manage your orders and payments in the Klarna app.
Part 2: Payments information
Pay in 30 days
Make your purchase today so you can try before you buy. Only pay for what you keep. Pay up to 30 days later. No interest. No fees. No impact to your credit score.
Paying after delivery allows you to try before you buy and is the easiest way to shop online.
- Complete the payment in full after purchase at no added cost.
- Report returns directly in our app and only pay for the items that you keep.
- Not making your payment on time could affect your ability to use Klarna in the future.
- Debt collection agencies are used as a last resort
You must be 18+ and a UK resident to be eligible for this credit offer. Pay Later Terms and Conditions
Pay in 3 interest-free instalments
Spread the cost of your purchase into 3 interest-free instalments. The first payment is made at point of purchase, with remaining instalments scheduled automatically every 30 days. No interest or fees. Select the Klarna option and enter your debit or credit card information. To check your eligibility, Klarna will perform a soft search with a credit reference agency. This will not affect your credit score.
No interest. No fees. No impact to your credit score.
- A new way to pay that's an alternative to a credit card.
- 3 instalments gives you flexibility to shop without interest or hidden fees. - Not making your payment on time could affect your ability to use Klarna in the future.
- Debt collection agencies are used as a last resort.
You must be 18+ and a UK resident to be eligible for this credit offer. Pay in 3 Terms and Conditions
Part 3: About Klarna
Pay online or in the app
Review your latest purchases and make payments in the Klarna app or online.
● Download the Klarna app: https://www.klarna.com/app
● Log in online: https://app.klarna.com/login
● Chat with customer service: https://www.klarna.com/uk/customer-service/
Safe and secure
With Klarna, you are always covered through Klarna’s Buyer Protection policy. Modern safeguards protect your information to prevent unauthorized purchases.Frequently asked questions
Visit our FAQ (https://www.klarna.com/uk/customer-service/) page to find out more about using Klarna.About Klarna
At Klarna, we have a relentless focus on creating the best shopping experience in the world. We believe payments are so much more than just a way to send money. That’s why our smooth checkout options give you more time and control so you can focus on the things you love.● More than 90 million shoppers are using Klarna.
● 200,000 retailers are working with us worldwide.
● We’re one Europe’s largest banks and we’ve been powering online checkouts for over 15 years.
Please spend responsibly. Borrowing more than you can afford could seriously affect your financial status. Make sure you can afford to make your monthly repayments on time.
R44 Performance Ltd. is not a lender and acts only as an introducer. The credit product is provided by Klarna Bank AB (publ). Credit is only available to permanent UK residents aged 18 and over, depending on their status. Terms and conditions apply. Please note that Pay in 30 days and Pay in 3 instalments are not regulated by the FCA.
BACKORDER - AVAILABLE
Pay later options
Spread the cost of your order. Choose your provider at checkout — nothing to set up here.
KLARNA FINANCE
Part 1: How it works
Shop now. Pay later with Klarna.
Please spend responsibly. Borrowing more than you can afford could seriously affect your financial status. Make sure you can afford to make your monthly repayments on time.
Step 1: Add products to your cart and select “Klarna” when you check out
Step 2: Enter a few personal details and you’ll know instantly if you’re approved
Step 3: Klarna will send you an email confirmation and reminders when it’s time to pay and you can manage your orders and payments in the Klarna app.
Part 2: Payments information
Pay in 30 days
Make your purchase today so you can try before you buy. Only pay for what you keep. Pay up to 30 days later. No interest. No fees. No impact to your credit score.
Paying after delivery allows you to try before you buy and is the easiest way to shop online.
- Complete the payment in full after purchase at no added cost.
- Report returns directly in our app and only pay for the items that you keep.
- Not making your payment on time could affect your ability to use Klarna in the future.
- Debt collection agencies are used as a last resort
You must be 18+ and a UK resident to be eligible for this credit offer. Pay Later Terms and Conditions
Pay in 3 interest-free instalments
Spread the cost of your purchase into 3 interest-free instalments. The first payment is made at point of purchase, with remaining instalments scheduled automatically every 30 days. No interest or fees. Select the Klarna option and enter your debit or credit card information. To check your eligibility, Klarna will perform a soft search with a credit reference agency. This will not affect your credit score.
No interest. No fees. No impact to your credit score.
- A new way to pay that's an alternative to a credit card.
- 3 instalments gives you flexibility to shop without interest or hidden fees. - Not making your payment on time could affect your ability to use Klarna in the future.
- Debt collection agencies are used as a last resort.
You must be 18+ and a UK resident to be eligible for this credit offer. Pay in 3 Terms and Conditions
Part 3: About Klarna
Pay online or in the app
Review your latest purchases and make payments in the Klarna app or online.
● Download the Klarna app: https://www.klarna.com/app
● Log in online: https://app.klarna.com/login
● Chat with customer service: https://www.klarna.com/uk/customer-service/
Safe and secure
With Klarna, you are always covered through Klarna’s Buyer Protection policy. Modern safeguards protect your information to prevent unauthorized purchases.Frequently asked questions
Visit our FAQ (https://www.klarna.com/uk/customer-service/) page to find out more about using Klarna.About Klarna
At Klarna, we have a relentless focus on creating the best shopping experience in the world. We believe payments are so much more than just a way to send money. That’s why our smooth checkout options give you more time and control so you can focus on the things you love.● More than 90 million shoppers are using Klarna.
● 200,000 retailers are working with us worldwide.
● We’re one Europe’s largest banks and we’ve been powering online checkouts for over 15 years.
Please spend responsibly. Borrowing more than you can afford could seriously affect your financial status. Make sure you can afford to make your monthly repayments on time.
R44 Performance Ltd. is not a lender and acts only as an introducer. The credit product is provided by Klarna Bank AB (publ). Credit is only available to permanent UK residents aged 18 and over, depending on their status. Terms and conditions apply. Please note that Pay in 30 days and Pay in 3 instalments are not regulated by the FCA.
With over five decades of expertise in radiator manufacturing, CSF stands as a leader in delivering superior cooling solutions. The CSF Audi B5 A4 1.8T High-Performance All-Aluminum Radiator exemplifies this commitment, engineered to maintain optimal engine temperatures and enhance the performance of your B5 A4 1.8T. Whether for daily driving or competitive motorsports, this radiator is meticulously designed to meet the rigorous demands of high horsepower applications and race environments requiring exceptional cooling capacity.
This radiator incorporates a 2-Row core featuring CSF's proprietary B-Tube Technology. Unlike conventional oval “O” type tubes, the innovative “B” shaped tubes are precision-formed and seam-brazed to achieve superior strength and durability. This advanced design allows the use of thinner, lighter aluminum material without compromising structural integrity, resulting in improved cooling efficiency. The unique inlet positioned in the middle of the brazed seam increases the heat transfer surface area by approximately 15% compared to standard tubes, effectively delivering the cooling performance of two smaller tubes within the same spatial constraints.
Additionally, the “B-tubes” facilitate dual liquid laminar flow, optimizing coolant movement through the radiator. Complementing this design, CSF employs ultra-efficient multi-louvered fins that are precisely aligned to maximize airflow across the radiator core. Each fin’s dimensions and orientation are carefully calculated and validated through extensive wind-tunnel testing to ensure maximum heat rejection efficiency, providing reliable cooling under demanding conditions.
The CSF B5 A4 1.8T radiator is engineered as a true “Drop-in fit” replacement, requiring no modifications for installation. All mounting brackets are CNC machined and welded to OE specifications, ensuring exceptional durability and precise fitment. The inlet and outlet connections are designed to match OEM configurations, allowing seamless integration with existing hoses—whether OEM or aftermarket—simplifying the upgrade process.
Features
- 2-Row, 42mm Ultra-High-Performance Dual Pass Core for enhanced cooling capacity
- 45 Cooling Tubes utilizing CSF's exclusive B-Tube Technology for superior heat transfer
- 6.5mm Tall Ultra Efficient Fins with Multi-Louvered Design to maximize surface area contact and airflow
- CNC Machined Mounting Brackets and OEM Style Inlet/Outlet connections for precise fit and durability
- Constructed from 100% All Aluminum with TIG-Welded joints ensuring strength and corrosion resistance
- Finished with a Smooth Satin coating for added protection and aesthetic appeal
- True Plug-and-Play “Drop-in Fit” installation requiring absolutely no modifications
- Designed exclusively for Manual Transmission applications
- Each unit is individually Leak and Pressure Tested to guarantee reliability
- Backed by a 2-Year Limited Warranty for peace of mind
Applications
| Year Range | Make | Chassis Code | Model | Trim | Engine / Trans / Etc | Notes |
|---|---|---|---|---|---|---|
| 1998 | Audi | B5 | A4 | Avant | Turbocharged 1.8L L4 (Manual) | - |
| 1997-2001 | Audi | B5 | A4 | - | Turbocharged 1.8L L4 (Manual) | - |
| 1998-2001 | Audi | B5 | A4 Quattro | Avant | Turbocharged 1.8L L4 (Manual) | - |
| 1997-2001 | Audi | B5 | A4 Quattro | - | Turbocharged 1.8L L4 (Manual) | - |
| 1998-2001 | Volkswagen | - | Passat | GLS | Turbocharged 1.8L L4 (Manual) | - |
OEM Part Numbers
- Audi: 8D0 121 251 P
- Audi: 8D0-121-251-P
- Audi: 8D0121251P
Warranty
Cooling Systems and Flexibles, Inc. (CSF) guarantees the quality and performance of its High-Performance Cooling Systems under normal use and service to the original purchaser of the vehicle in which the product was originally installed. For comprehensive warranty details, please visit our Warranty Page.
SKU# 7204 Warranty Term: 2 years
In summary, the CSF Audi B5 A4 1.8T High-Performance All-Aluminum Radiator represents a pinnacle of engineering excellence, combining innovative design with precision manufacturing to deliver reliable, efficient cooling. Its robust construction, advanced B-Tube Technology, and meticulous testing ensure that your vehicle maintains optimal operating temperatures under all conditions, safeguarding engine performance and longevity. Trust CSF to provide a high-quality, durable radiator that meets the exacting standards of both enthusiasts and professional racers alike.
Unless explicitly stated otherwise, all products sold by R44 Performance Limited are designated RACE ONLY and are solely for competition or off-road use limited to racing formally sanctioned by a recognized racing organization. Any other use, including recreational off-road use, may violate local, state, and Federal laws. R44 Performance Limited does not implicitly or explicitly confirm the legality of using any products it sells on public roads; that is entirely the responsibility of the consumer.
It is the responsibility of the customer to check with all federal, state local and environmental laws before ordering and installing a product. R44 Performance Limited is not responsible for any fees, fines or costs that a customer may incur as a result of failing to check with federal, state, local or environmental laws before ordering and installing a product.
We get a large number of custom orders and requests everyday, so as a result it is not always possible for us to keep every item in stock at all times in our warehouse. If you require the item urgently please contact our sales team here to check the stock before you make your purchase.
We totally understand if you're not certain a part will be compatible with your car, so we highly recommend contacting us here with your query. Our friendly sales team will then be in touch to confirm if this part is the correct part you are looking for.
All in stock products ship the same day if ordered before 2pm GMT
For out of stock items we will contact you with an estimated wait time if not otherwise specified above.
We offer worldwide shipping on all products. If upon receiving your product you wish to return; we offer a 30-day returns policy. For our in-depth returns information please follow the link. "R44 Returns Policy
All of our products come with a standard warranty of 1-3 years. This is dependant on the type of product however. For more details please see our warranty page here.
PLEASE NOTE
- Orders with both in-stock and backorder or out-of-stock products will be dispatched once all products are available to ship together.
- Contact our sales team if you want your parts fitted to your vehicle at our London workshop.
- Shipping estimates are based on courier delivery times and don't include time to despatch from our warehouse.