The 4-series was the successor of the 3-series and was offered in five engine combinations and four chassis types. Production of Scania 4-series was stopped after its successors P-series, R-series and T-series were introduced in 2004.
The engine sizes are - as usual for the 1-4 series - shown in the model name with a number constructed by the cylinder volume in litres followed by the generation of truck. This way a 14 litre engine in the 4-series will be a 144.
The letter following the number describes the chassis type, but in the 4-series this code changed compared to former series. (details needed)
The 4-series changed the well-known Scania front look from quite square and lined to new round and curved shapes. The new cab design also split the grill in two horizontally, making the lower part flip down to make a step usable for better reach when cleaning windows or eventually as a bench while waiting somewhere.
The 4-series was succeeded by the R/P/G-series in 2004, with these technically the 5-series.