Many BMW i3 and i3s 20-inch set-ups use 175/55 R20 on the front axle, with a different size on the rear. Check the tyre placard on the door shut or fuel flap and match what is listed for your exact wheel option. Replace tyres in pairs on the same axle to keep handling and stability consistent.
175 is the tyre width in millimetres, 55 is the sidewall height as a percentage of the width, R means radial construction, and 20 is the rim diameter in inches. It must match your wheel diameter exactly, and it also needs to suit the wheel width your vehicle is approved to use. Confirm the size on your current tyre sidewall and cross-check the vehicle handbook before ordering.
Choose the same load index and speed rating shown on your vehicle placard or current tyres, and never go lower. A higher rating is usually acceptable, but it must still be compatible with your vehicle and any manufacturer requirements. This is especially important on EV applications where kerb weight and instant torque can make the correct specification more critical for wear and safety.
Options can be limited because 175/55 R20 is a specialist size, so stock varies by brand and season. If you drive year-round and want fewer tyre changes, an all-season pattern can be a practical choice where available. If you need a full winter set and choices are restricted, some drivers use an approved smaller wheel and tyre package for winter, but you should only do this if it is manufacturer-approved for your car.
175/55 R20 is produced in lower volumes than mainstream 20-inch sizes, so there are fewer patterns and less price competition. The tyres are also often engineered for efficiency and controlled handling on lighter, narrower wheel fitments, which can raise manufacturing complexity. Comparing available brands and ordering before your tread gets too low usually gives you the best choice and value.
