do88 Performance Transmission Cooler for BMW G Series B48 B58

£438.42 Inc Vat

Upgrade your car’s performance with the do88 Performance Transmission Cooler!


SKU: DO88OC-190 Category: Tag:


To Fit:
BMW 2′ M240i M240iX (G42) – Engine: B58 – 2022 on
BMW 3′ 330e (G20 G21) – Engine: B48X – 2018 on
BMW 3′ M340i M340iX (G20 G21) – Engine: B58 – 2018 on
BMW 4′ M440i M440iX (G22 G23 G26) – Engine: B58 – 2021 on
BMW Z4 M40i (G29) – Engine: B58 – 2018 on


Designed specifically for BMW M340i/Z4 and Toyota GR Supra, the do88 Automatic Transmission Cooler ensures smooth and efficient shifting. While the latest Supra / M340i / Z4 lacks the manual gearbox, the swift ZF 8HP transmission coupled with the B58 compensates impressively. Yet, like all sports cars, heat remains a significant challenge, especially in tuned cars that generate more heat during rigorous street, track, or drag strip driving.

Our solution

The 2019+ BMW M340i/Z4 and GR Supra models come with an external liquid-to-air transmission cooler. However, for tuned cars, the generated heat can often exceed the OE cooler’s capacity. Recognising this, our engineers redesigned the transmission cooler’s core, increasing its volume by 184% and the cooling surface area by 176% while maintaining similar fluid pressures. We upgraded the tubes with harmonica tubes with internal channels, ensuring optimal cooling efficiency. Whether you’re spending a day on the track or enjoying a drive through the back roads, the do88 Transmission Cooler helps keeping the temperatures in check.


Installing the much larger do88 Performance Transmission Cooler is hassle-free, requiring no modifications (see installation instructions).

Key Features:

Core volume increased by 184% and the active cooling area by 176% compared to the original cooler (OE).
Harmonica tubes ensure optimal oil flow and maximum surface area contact.
Compatible with the do88 Front Intercooler Radiator (WC-400).
OEM-style “Quick Connect” inlet/outlet connections.
Drop-in fit, eliminating the need for modifications.