The 3.0-litre (approx 245 bhp (183 kW) at 6200 rpm)[citation needed] engine was based on the Straight-6 design of the Maserati 250F and incorporated a lengthened stroke developed by Vittorio Bellentani to increase the capacity from the original 2.5-litres.

The compression ratio was reduced from 12:1 to 9.5:1, partly due to the FIA regulations requiring the engine to be run on road car fuel.

New features for the 300S included the incorporation of a De Dion type rear axle, a transverse four-speed gearbox and two chain driven camshafts.

[1][2] Mark Knopfler, originally of Dire Straits, is a long term owner of a 300S and has raced the car in historic competitions.

[4][5] Additionally he featured the lines "If I was a Maserati, A red 300s, I'd ride around to your house, baby, Give you a driving test."