The Mack B series is a model line of trucks produced by Mack Trucks between 1953 and 1966. The successor to the 1940-1956 Mack L series, the B-series was a line of heavy conventional-cab trucks. Adopting a more streamlined appearance over its predecessor, the B-series was designed with a sloped windshield and larger, rounded fenders The model line was sold in multiple configurations, including tractors and straight/rigid trucks, cowled chassis (delivery body or bus), or fire trucks. The B-series was the first Mack truck produced with a diesel engine, introducing the Mack-produced Thermodyne inline-6 in 1953. During 1966, Mack replaced the B-series with the Mack R-series, which lasted into the 21st century. In total, 126,745 examples of the B-series were produced over 13 years.

Model numbers & letters

Chassis model designations: Chassis letter guide:

Engines

The B Model offered 10 different gasoline engines, from a 291 cuin with 107 hp in the B20 to a 707 cuin with 232 hp in the B70. A wide range of diesels were also offered. From the B61 up to the ENDT 673 turbocharged I6 and END 864 V8 were offered. From the B73 up to the Cummins 855 cuin I6s up to the NTC335 were available. The table shows the largest gasoline and diesel engines in the series. (Type: G=gasoline, D=diesel, TD=turbocharged diesel)