M135i LCI (F20 & F21)

The 2015 Life Cycle Impulse (facelift) raised the N55's output from 320PS to 326PS, with torque unchanged at 450Nm. Styling was updated with revised headlights, new front and rear bumpers and redesigned LED rear lights, and the interior and infotainment received detail changes. Mechanically the car is very similar to the pre-LCI M135i, so most engine, suspension and brake upgrades are shared, but exterior parts need to match the facelift body.

Usually not. The facelift brought different front and rear bumpers and rear lights, so splitters, diffusers, side skirts in some kits and rear valances are often specific to either pre-LCI or LCI cars. Interior parts such as steering wheels, paddle shifters and gear selectors are generally shared, as are most suspension and brake components. Check that any exterior styling part is listed for the LCI before ordering.

Yes, if you choose a wheel built around the factory frame. Most F2x upgrade wheels reuse your original airbag, buttons and, where fitted, the shift paddles, so safety equipment and functions are retained. Check whether your car has a heated wheel or adaptive cruise buttons, as some wheels need the matching harness or minor coding. Universal motorsport wheels that remove the airbag are intended for track cars, not road use.

For owners who use manual mode, yes. The factory plastic paddles are small and sit close to the wheel rim, so larger aluminium or carbon paddles with a firmer click are easier to find mid-corner and feel more precise. They bolt on in place of, or over, the originals and do not change how the ZF eight-speed shifts. Gear selector upgrades are another popular interior change on automatic cars.

The LCI uses the same N55 as the earlier car, so gains are similar. A Stage 1 remap on standard hardware is commonly reported at around 360–380bhp, and close to 400bhp with supporting parts such as an intake, aluminium charge pipe and sports-cat downpipe. The single twin-scroll turbo is the limiting factor beyond that. Healthy coil packs, spark plugs and a leak-free boost system matter more than headline figures.

Start with the known N55 wear items. The electric water pump and thermostat are common failures, coil packs and spark plugs should be in good condition, and the oil filter housing gasket can leak with age. Direct injection also means carbon can build up on the intake valves, especially on cars used for short journeys. A boost leak test and a healthy service history make any later modification more reliable.