It makes no sense when the M2 is available for only a small premium.
The BMW M235i has just barley been surpassed by the strong-selling M2, but BMW already wants to give the baby M a refresh. To do so, it will make the same changes that it made when it converted the 335i into the 340i, which means replacing the twin turbo N55 six-cylinder engine with its newest twin turbo inline six B58 engine. The new M235i will be called the M240i and should feature a bump in horsepower from 320 hp to 340 ponies. Torque should go up too from 330 lb-ft to 360 lb-ft, meaning smoking the rear tires should be slightly easier.
The B58 engine is also a 3.0-liter like the N55, but it is now based on modular architecture meaning that it will share parts with other BMW engines. Expect the aggressive suspension setup that made the M235i a sports car to stay in the M240i along with the e-differential, front fascia, and an xDrive option for non-purists. Even though this won't affect Americans, Europe will get the same new engine on the impressive M135i hatchback, earning it the M140i moniker. Expect the same six speed manual and eight-speed auto to be optional on all engine converts. Now, all of this is irrelevant simply because the M2 exists and can be had for $52,000, compared to the $50k price of a fully loaded M240i. We should see the new cars this summer.