The next significant change occurred in 1962, when the B16 was replaced by Volvo's new B18 engine, initially developed for the P1800 sports car introduced the previous year. This 1.8 L engine had five main bearings. Again single and twin carburettor versions were offered, designated B18A and B18D, respectively. The U.S. market saw very few B18A cars since the United States' public prioritised performance over fuel economy. Also in 1962, Volvo changed from 6- to 12-volt electrical systems. In 1963 Volvo began producing the 544 at their new Canadian Dartmouth/Halifax plant, the first Volvo plant to be located outside of Sweden.