The B18 is a 1.8 L inline four cylinder overhead valve automobile engine produced by Volvo from 1961 through 1968. A larger 2.0 L derivative called the B20 debuted in 1969.

Despite being a pushrod design, the engines can rev to 6,500 rpm. They are also reputed to be very durable. The world's highest mileage car, || at 2800 rpm || at 2600 rpm