Worried that the costly 911 would narrow its customer base and affect sales, Porsche needed an entry-level model for people who wanted an everyday sports car that was dependable and economical. In those days, nobody considered the economy of performance models, but Porsche realized it could be a good selling point (via Porsche).
So, in 1965 after the end of the Porsche 356 production, they released the new 912. It was a 911, but with a 2.0-liter, flat four-cylinder engine producing 90 HP and modest performance numbers. The car also costs significantly less than the 911 and was fuel-efficient at 36 mpg. You thought all Porsches are fast, but not all of them were. This model proved that.