Name: do88 S58 Auxiliary Radiator BMW G8X M2 M3 M4
Brand: DO88
SKU: WC-440
Price: 471.00 GBP
Availability: InStock

Product Description

The do88 Auxiliary Radiator is a direct-fit cooling upgrade for BMW G8X M-cars fitted with the S58 engine, designed to improve coolant temperature control under sustained load. Developed for high-performance road, tuned and track-driven applications, it replaces the factory auxiliary radiator with a larger, stronger and more efficient all-aluminium unit.

The BMW S58 cooling system uses a three-radiator layout, with one central main radiator supported by two smaller auxiliary radiators positioned at the corners of the car. These auxiliary radiators play an important role in controlling coolant temperatures during hard driving, but the factory units use slim cores and plastic end tanks, which can become a limitation on tuned or heavily used vehicles.

do88’s auxiliary radiator increases cooling capacity with a 43% larger core volume, a dual-row 48mm thick core and a 13% increase in active cooling area compared with the original BMW radiator. This larger and more efficient design helps reduce heat soak and supports more stable coolant temperatures during repeated full-throttle use, track sessions and hot operating conditions.

Durability is also significantly improved thanks to the full aluminium construction and TIG-welded end tanks, removing the weaker plastic end tanks found on the factory radiators. OE-style quick connect fittings, CNC-machined mounting points and compatibility with the factory rock guards help keep installation straightforward while retaining practical protection.

Sold individually for left or right-side fitment, this do88 auxiliary radiator is a worthwhile cooling and reliability upgrade for S58-powered BMW M2, M3 and M4 builds where consistent thermal management is a priority.

Further information below.

Key Features

43% larger core volume vs. OEM
Dual-row 48mm thick core
13% larger active cooling area
All-aluminium construction with TIG-welded end tanks
OE-style quick connect fittings for easy installation
CNC-machined mounting points
Compatible with factory rock guards
Direct-fit for both left and right sides
Sold individually (one per side)

Vehicle Compatibility

BMW G87 M2 (2023–202X)
BMW G80 M3 / M3 Competition / M3 CS (2020–202X)
BMW G82 / G83 M4 / M4 Competition / M4 CSL (2020–202X)
For S58 engine cars only

Note: Sold individually – two required per car.

What's Included

DO88 S58 Auxiliary Radiator BMW G8X M2, M3 & M4
Please refer to the manufacturer kit contents for final hardware confirmation before installation

Note: Sold individually – two required per car.

FAQs

Will the do88 auxiliary radiator fit the BMW G80 M3, G82 M4 and G87 M2?

Yes. This do88 auxiliary radiator is designed for BMW G8X M-cars fitted with the S58 engine, including G80/G81 M3, G82/G83 M4 and G87 M2 applications, subject to the stated product fitment.

Why upgrade the factory auxiliary radiators?

The factory auxiliary radiators use slim cores and plastic end tanks, which can become a limitation on tuned or hard-driven S58 cars. Upgrading to do88’s larger all-aluminium radiator helps improve cooling capacity and long-term reliability.

How much larger is the do88 auxiliary radiator compared with OEM?

The do88 auxiliary radiator offers a 43% increase in core volume and a 13% increase in active frontal cooling area compared with the factory unit.

What core does this radiator use?

It uses a dual-row 48mm thick core, designed to increase coolant capacity and improve heat rejection under sustained load.

Is this radiator suitable for track use?

Yes. The larger core volume, increased cooling area and TIG-welded aluminium construction make it well suited to track days, tuned cars and high-performance road use where coolant temperatures need to remain stable.

Does it replace both auxiliary radiators?

No. The radiator is sold individually, with one unit required per side. It is designed as a direct-fit replacement for either the left or right auxiliary radiator depending on the selected application.

Can I retain the factory rock guards?

Yes. The do88 auxiliary radiator is compatible with the factory rock guards, helping retain protection while improving cooling performance.

Is installation straightforward?

Yes. The radiator uses OE-style quick connect fittings and CNC-machined mounting points for direct-fit installation. Professional installation is still recommended to ensure correct fitment, bleeding and coolant system operation.

What supporting upgrades work well with this radiator?

For higher-output or track-focused S58 builds, supporting upgrades such as the do88 front intercooler radiator, do88 inlet manifold with integrated intercooler, do88 charge pipes, upgraded coolant hoses and motorsport-grade coolant fluid may further improve thermal management.

Shipping & Delivery

Dispatch Times

Most stocked items dispatch within 1–2 business days. Some products may have longer lead times due to special ordering, availability, or build times. If your order contains multiple items, they may be shipped together once all items are ready unless otherwise agreed.

UK & International Shipping

We ship worldwide. Transit times vary depending on destination and courier. Tracking details are provided once your order is dispatched.

Import Duties & International Orders

International customers are responsible for all import duties, taxes, and clearance fees. These are not included in our prices and are outside of our control. Refusal or non-payment of import charges may result in return shipping, handling fees, and customs charges being deducted from any refund.

Damaged Shipments

If your parcel arrives visibly damaged, please refuse delivery or note the damage with the courier. If damage is discovered after opening, contact us immediately with photos. Do not install damaged items, as installation voids courier claims and return eligibility.

Returns

Returns must be authorised before sending anything back. Returns must be requested within 14 days of delivery and returned within 14 days of approval, in unused/uninstalled condition and in original packaging. Some items, including special-order, built-to-order, used, installed, or modified parts, are non-returnable.

Full details are available in our Shipping Policy and Returns & Refund Policy.

Warranty & Disclaimer

Warranty

Most products include a manufacturer’s warranty covering manufacturing defects only. Warranties do not cover wear and tear, improper installation, misuse or neglect, track use, competition or racing environments, labour costs, vehicle damage, downtime, or consequential loss. Warranty outcomes are determined by the manufacturer, not Clubsport Garage. Items must be returned for inspection at the customer’s cost unless agreed otherwise.

Fitment & Installation

Many products are aftermarket components and may require professional installation or minor adjustment. Perfect OEM-level fitment cannot be guaranteed. Professional installation by an experienced workshop is strongly recommended. Installed or used items cannot be returned.

Motorsport Use Disclaimer

Some products are intended for off-road, track, or motorsport use only and may not be legal for road use, for example non-TÜV/DOT-approved parts. It is the customer’s responsibility to ensure compliance with local laws, insurance requirements, and vehicle regulations. By purchasing and installing aftermarket parts, you accept all responsibility for ensuring compatibility, legal compliance, proper installation, and any resulting wear, damage, or failure.

Product Images & Descriptions

Product photos are illustrative and may differ slightly from the item supplied. If specific details are important, please contact us before purchasing.

Full details are available in our Terms of Service and related policy pages.