The 'i' in BMW's model nomenclature originally stood for gasoline injection systems. Over the years, other letters have been used: 'd' for diesel engines and 'e' for hybrids. Recently, BMW started using 'i' at the beginning of its EV models like the i4 and i5.
The redefinition of the 'i' badge began with the introduction of the BMW i3. This model initially included a gas-powered range extender version but has since evolved. Bernd Körber, Senior Vice President at BMW Brand and Product Management, explained on BMW Blog why they preserved the 'i'. "Historically, even though our interpretation of BMW i was always different, it’s more innovation, not necessarily only electric, and we historically had injection at the end [of the badge], we said, we would like to keep ‘i’ as an asset, and we would like to keep it as a signature to indicate you’re driving an electric car and that was the logic that we had."
Updates applying this new designation system will start rolling out this year for models like the 1-Series, 2-Series, and the X3.
Source: BMW Blog
