BMW i3 gearbox: on this premium electric city car, it is more accurate to speak of a single-speed automatic transmission. Unveiled in 2011 and on sale from 2013, the i3 won over more than 250,000 buyers before production ended in 2022, making it a highly sought-after used model. Its transmission has a strong reliability record, but it is not immune to faults. Here is a practical guide to maintaining it and knowing when to have it repaired.
How does the BMW i3 gearbox work?
Since 2013, the i3 has gone through several battery upgrades to extend its range. The latest version, the i3s launched in 2017, features a 42.2 kWh battery pack offering around 305 km of range on a single charge.
Whether fully electric or plug-in hybrid, the i3 uses a single-speed automatic gearbox, also known as a single-ratio transmission. Unlike conventional multi-speed gearboxes, it does not change gear: the 170 hp synchronous electric motor delivers 125 kW of power across the entire rev range, managed by electronic control rather than a set of multiple gear ratios. For a more detailed explanation of how this works, see our guide on how a gearbox works.
How do you maintain the BMW i3 automatic transmission?
Contrary to popular belief, an automatic transmission requires regular servicing and a few precautions to reduce the risk of breakdown. With an i3, keep the following good habits in mind:
- follow the transmission fluid change intervals recommended by the manufacturer;
- check the transmission oil level regularly and replace it if it appears black or has an unpleasant smell;
- use the correct oil for an automatic gearbox, as specified in the vehicle handbook or by a specialist;
- keep the cooling system properly maintained;
- ensure the vehicle has come to a complete stop before selecting a driving mode;
- minimise towing and arrange an annual transmission service.
Transmission oil plays a central role: it lubricates the reduction gear, dissipates heat and protects moving parts. Regular checks are therefore the best form of prevention.
When should the BMW i3 gearbox be repaired?
Over time, the transmission may show signs of failure that are best identified early. Gearbox slipping means it is no longer transferring engine power to the wheels correctly: the motor revs too high or the car struggles to move forward. This can be caused by low oil pressure, worn clutch discs or a faulty speed sensor.
Other warning signs to watch out for include a sudden or violent jolt, or the transmission locking up entirely, which is often linked to an electrical or mechanical fault. In all cases, an electronic diagnostic carried out by a professional will pinpoint the cause accurately before any repair work begins.
Do you own another electrified BMW model? Read our advice on the BMW i4 gearbox and the BMW i8 gearbox.
Frequently asked questions
Does the BMW i3 have a real gearbox?
It has a single-speed automatic transmission. There is no gear changing: a reduction unit transfers the torque from the electric motor to the wheels.
Does the i3 transmission need an oil change?
Yes. Even as a single-speed unit, the gearbox contains lubricating oil that should be checked and replaced at the recommended intervals to preserve its reliability.
My i3 is slipping and the motor is revving high – what should I do?
This symptom indicates a transmission that is no longer transferring power correctly. Have a diagnostic carried out promptly, as the problem may stem from oil pressure, the clutch discs or a sensor.
Is it better to repair or replace the i3 transmission?
It depends on the diagnostic findings. When the gearbox is too badly damaged, a reconditioned unit on an exchange basis offers a reliable and environmentally friendly alternative to a new part.
Why choose EDEN BOITES?
At EDEN BOITES, every transmission is reconditioned on an exchange basis: stripped down, inspected, faulty components replaced and tested before going on sale. You benefit from a warranty of up to 24 months and a satisfaction-or-money-back guarantee on the exchange, subject to our Terms and Conditions. Payment can be spread over up to 10 instalments, and delivery is available throughout France and the European Union, with lead times confirmed on quote. Browse our BMW range or our full selection of gearboxes to find the right reference for your i3.
