The first two running prototypes of Porsche's M28 V8 used one four-barrel carburetor for initial testing. Actual production cars employed the planned Bosch K-Jetronic fuel injection system. When increasing concern within the company over price and availability of fuel during the oil crisis of the 1970s became an issue of contention, smaller engines were considered in the interest of fuel economy. A push began for the development of a 3.3 L powerplant envisioned by Fuhrmann, but company engineers balked at this suggestion. Both sides finally settled on a 4.5 L, SOHC per bank 16-valve V8 rated at ( in North America), which they considered to have an acceptable compromise of performance and fuel economy.