BMW is keeping tight-lipped about the project, but Auto Express speculates that the i4 will take the form of a fashionable city car. Whereas the i3 is intended to be a practical runabout for the masses, the i4 will give up some of that versatility in the name of style.
Not much else is known about the i4, but it could borrow its powertrain from the i3. The rear-wheel drive i3 is powered by an electric motor generating 170 horsepower and 184 lb-ft of torque. BMW hasn't provided specs for the i3's battery pack, but says the car is capable of "travel long distances on a single charge."
As with both the i3 and i8, the i4 is expected to be comprised largely of carbon fiber and other lightweight materials. That should ensure performance to match the i4's cheeky looks.
No word on when the i4 might go on sale, but be sure to check back for more details following the i4's official debut on November 28.